Three-dimensional topography of rat trigeminal ganglion neurons using a combination of retrograde labeling and tissue-clearing techniques.

The trigeminal nerve is the sensory afferent of the orofacial regions and divided into three major branches. Cell bodies of the trigeminal nerve lie in the trigeminal ganglion and are surrounded by satellite cells. There is a close interaction between ganglion cells via satellite cells, but the function is not fully understood. In the present study, we clarified the ganglion cells' three-dimensional (3D) localization, which is essential to understand the functions of cell-cell interactions in the trigeminal ganglion. Fast blue was injected into 12 sites of the rat orofacial regions, and ganglion cells were retrogradely labeled. The labeled trigeminal ganglia were cleared by modified 3DISCO, imaged with confocal laser-scanning microscopy, and reconstructed in 3D. Histograms of the major axes of the fast blue-positive somata revealed that the peak major axes of the cells innervating the skin/mucosa were smaller than those of cells innervating the deep structures. Ganglion cells innervating the ophthalmic, maxillary, and mandibular divisions were distributed in the anterodorsal, central, and posterolateral portions of the trigeminal ganglion, respectively, with considerable overlap in the border region. The intermingling in the distribution of ganglion cells within each division was also high, in particular, within the mandibular division. Specifically, intermingling was observed in combinations of tongue and masseter/temporal muscles, maxillary/mandibular molars and masseter/temporal muscles, and tongue and mandibular molars. Double retrograde labeling confirmed that some ganglion cells innervating these combinations were closely apposed. Our data provide essential information for understanding the function of ganglion cell-cell interactions via satellite cells.

Circadian rhythm of PERIOD2::LUCIFERASE expression in the trigeminal ganglion of mice.

Introduction: The trigeminal nerve conveys delicate sensations such as warmth, pain, and tactile pressure in the oral and facial regions, and most trigeminal afferent cell bodies are located in the trigeminal ganglion. Our previous study has shown that sensations in trigeminal nerve innervated areas, specifically in the maxillofacial region, exhibit diurnal variation and that sensitivity changes time-dependently. In this study, we aimed to clarify the rhythm of expression of clock gene in the trigeminal ganglion of mice to elucidate the mechanism of circadian regulation in the same area. Methods: Immunohistochemistry examined the expression of the PER2 protein in the suprachiasmatic nucleus and trigeminal ganglion of wild-type mice. To measure gene expression as bioluminescence, PERIOD2::LUCIFERASE knock-in (PER2::LUC) mice were used. Unilateral trigeminal ganglion and brain sections including the suprachiasmatic nucleus were incubated ex vivo. Bioluminescence levels were then measured using a highly sensitive photodetector. The same experiments were then conducted with Cry1 gene-deficient (Cry1-/- ) or Cry2 gene-deficient (Cry2-/- ) mice. Results: In the trigeminal ganglion, immunohistochemistry localized PER2 protein expression within the neuronal cell body. Mouse trigeminal ganglion ex vivo tissues showed distinct circadian oscillations in PER2::LUC levels in all genotypes, wild-type, Cry1-/- , and Cry2-/- . The period was shorter in the trigeminal ganglion than in the suprachiasmatic nucleus; it was shorter in Cry1-/- and longer in Cry2-/- mice than in the wild-type mice. Conclusion: The expression of Per2 in neurons of the trigeminal ganglion in ex vivo culture and the oscillation in a distinct circadian rhythm suggests that the trigeminal ganglion is responsible for the relay of sensory inputs and temporal gating through autonomous circadian oscillations.

Estimation of the Risk of Postoperative Hypertension Following Minor to Moderate Surgery Using an Echocardiogram and Biomarkers.

This study aimed to determine independent factors for developing postoperative hypertension using 4 biomarkers in patients receiving oral and maxillofacial surgery under general anesthesia. Brain natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity myocardial troponin T (hs-TnT), and high-sensitivity myocardial troponin I (hs-TnI) were measured and preoperative echocardiograms were examined. Episodes of systolic blood pressure (SBP) ≥ 170 mmHg or diastolic blood pressure ≥ 100 mmHg within 1 week after surgery were considered postoperative hypertension. We analyzed 213 (130 men; 83 women) patients, who were divided into a postoperative hypertension group (HT group, n = 32) and a normal group (N group, n = 181). The HT group showed a higher LVMI (113.5 versus 100.1), higher E/e' of the lateral wall (9.1 versus 7.7), and higher BNP (39.2 versus 22.9 pg/mL), NT-proBNP (400.1 versus 143.9 pg/mL), and hs-TnT (15.6 versus 10.3 ng/L) concentrations compared to the N group. NT-proBNP and hs-TnT concentrations positively associated with E/e', but BNP and hs-TnI did not. NT-proBNP (AUC = 0.64, cutoff value: 117.0 pg/mL) and hs-TnT (AUC = 0.61, cutoff value: 11.0 ng/L) concentrations were effective for discriminating E/e' ≥ 12. Multivariate logistic regression analyses showed that risk factors responsible for developing postoperative hypertension were NT-proBNP and hs-TnT using biomarkers and E/e' as independent variables, and NT-proBNP and SBP at admission using biomarkers and SBP at admission as independent variables. These findings suggest that NT-proBNP and hs-TnT concentrations, and SBP at admission, are useful to predict postoperative hypertension after minor to moderate surgery, and that left ventricular filling pressure is a primary factor associated with postoperative hypertension.

Role of heterozygous and homozygous alleles in cryptochrome-deficient mice.

The circadian rhythms of physiology and behavior are based on molecular systems at the cellular level, which are regulated by clock genes, including cryptochrome genes, Cry1 and Cry2. In mammals, the circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus maintains the circadian rhythms throughout the body. Cry1 and Cry2 play distinct roles in regulating the circadian rhythm. However, the different effects of manipulating clock genes in heterozygous and homozygous alleles, Cry1 and Cry2, remain unclear. Therefore, this study aimed to understand the haplosufficiency of cryptochrome genes in regulating the circadian system. We examined wheel-running activity rhythms and PER2::LUC expression rhythms in SCN slices and pituitary explants in mice. Compared with wild-type mice, Cry1-/- or Cry2-/- mice had shortened or lengthened periods in free-running behavioral rhythms and PER2::LUC expression in the SCN and pituitary gland. Cry1+/- mice had similar circadian rhythms as wild-type mice, although Cry2+/- mice had lengthened periods. The amplitude of PER2::LUC expression exhibited faster damping in Cry1-/- mice. Therefore, Cry1 deficiency affects the circadian period length and stability of the circadian system. A single allele of Cry2 deficiency affects the circadian rhythm, whereas that of Cry1 deficit is compensated.

Diurnal Variation in Trigeminal Pain Sensitivity in Mice.

Management of time and circadian disruption is an extremely important factor in basic research on pain and analgesia. Although pain is known to vary throughout the day, the mechanism underlying this circadian variation remains largely unknown. In this study, we hypothesized that the process of pain transmission to the central nervous system (after receiving nociceptive stimuli from outside the body) would show day-night differences. Ten-week-old male mice were kept under a strict 12/12-h light/dark cycle for at least 10 days. Formalin was then injected into the second branch region of the trigeminal nerve and the duration of pain-related behaviors (PRBs) was assessed. Immunohistochemical staining was then performed, and the c-Fos-immunopositive cells in the trigeminal spinal tract subnucleus caudalis (Sp5C) were counted. The results showed that the duration of PRBs was longer and the number of c-Fos immunopositive cells in the Sp5C was higher at nighttime than during the day. In addition, the trigeminal ganglia (TG) were extracted from the mice and examined by quantitative real-time PCR to evaluate the daytime and nighttime expression of nociceptive receptors. The results showed that the mRNA expression of transient receptor potential ankyrin 1 in the TG was significantly higher at night than during the day. These results suggest that pain in the trigeminal nerve region is more intense at nighttime, when rodents are active, than during the daytime, partly due to differences in nociceptor expression.

Ultrasound-guided inferior alveolar nerve block for trismus during dental treatment: a case report.

BACKGROUND: Temporomandibular disorder (TMD) is a broad term that encompasses pain and/or dysfunction of the masticatory musculature and TM joints (TMJs). When TMD becomes a chronic condition, the symptoms are extremely difficult to manage and require multiple interventions. CASE PRESENTATION: A woman in her 50s developed TMD after a traffic accident 30 years ago. The patient presented with severe trismus due to TMJ pain and a maximum mouth opening of 20 mm. Ultrasound-guided inferior alveolar nerve block (IANB) was performed with ropivacaine. After IANB, the pain during mouth opening subsided and the maximum mouth opening improved to 40 mm. Dental treatment could be performed without difficulty and the patient could keep her mouth open throughout the treatment. CONCLUSIONS: Treatments for chronic TMD are limited and it is necessary to identify the precise etiology before choosing a treatment option. In this patient, ultrasound-guided IANB proved to be effective in relieving TMD-related trismus.

The State Anxiety Inventory Is Useful for Predicting the Autonomic Nervous System State of Patients Before the Extraction of an Impacted Mandibular Third Molar.

PURPOSE: Dental anxiety about extraction of impacted mandibular third molars changes the activity of the autonomic nervous system. Thus, to provide safe dental treatment, it is important that a surgeon be aware of a patient's pretreatment anxiety and autonomic nervous system state. Therefore, we analyzed how a scheduled treatment to extract mandibular third molars affects the pretreatment electroencephalogram (EEG), autonomic nervous system, and psychological state of patients. We compared their findings with those of volunteers not scheduled to undergo dental treatment. PATIENTS AND METHODS: The study enrolled 30 patients who were scheduled to undergo impacted mandibular third molar extraction (ie, pretreatment group) and 30 volunteers who were not (ie, control group). Heart rate variability and an EEG were recorded during the experiment. The State Anxiety Inventory-State Anxiety scale (STAI-S) scores were recorded before the procedure. For the statistical analysis, P < .05 was deemed statistically significant. RESULTS: High-frequency (HF) variability was significantly decreased and the STAI-S score was significantly increased in the pretreatment group compared with the control group (P < .01 for both). The low frequency (LF)/HF ratio and alpha-wave activity showed a significant negative correlation on both sides in the control group (P < .01); however, no correlation existed in the pretreatment group. The LF/HF ratio and STAI-S score showed a significant positive correlation in the pretreatment group (P < .05); however, no correlation existed in the control group. CONCLUSIONS: Predicting a patient's autonomic nervous system state before dental treatment based on the EEG was difficult. The STAI-S psychological test was a useful method.

Time to Recovery of Feeding After Alveolar Bone Graft Is Associated With Postoperative Nausea and Vomiting Within 2 Hours in Children.

OBJECTIVE: To examine the relationship between the method of anesthesia for alveolar bone graft surgery and postoperative nausea and vomiting (PONV) based on the difference in surgical timing and to assess factors related to the postoperative quality of life. DESIGN: Retrospective observational study. SETTING: Hospital. PARTICIPANTS: Patients with cleft lip and palate who underwent alveolar bone graft surgery under general anesthesia. The subjects were divided into two groups based on surgical timing: secondary bone graft (SBG) and late secondary bone graft (LSBG) groups. MAIN OUTCOME MEASURES: Relationship between time to recovery of feeding and the types of anesthesia, PONV, and postoperative pain period. RESULTS: The mean patient age was 9.97 ± 1.33 years in the SBG group and 15.39 ± 0.31 years in the LSBG group. In the SBG group, patients who were administered fentanyl or remifentanil had significantly higher incidence of PONV than those who were not administered these drugs. In the SBG group, the time to recovery of feeding was significantly longer in patients experiencing PONV within 2 hours or that lasted for 24 hours than in those without PONV. In the LSBG group, there was no significant difference regarding any of the above factors. CONCLUSIONS: Our results suggest that the occurrence of PONV within 2 hours or lasting for 24 hours postoperatively in school-age children prolonged the time to recovery of feeding. This indicates that the time to recovery of feeding can be predicted based on the occurrence of PONV within the first 2 hours.

The Effects of Music Listening During Extraction of the Impacted Mandibular Third Molar on the Autonomic Nervous System and Psychological State.

PURPOSE: Pain, anxiety, and nervousness related to dental procedures can cause acute changes in the autonomic nervous system. Music is widely accepted as a relaxation method during dental treatment; however, its effects during dental treatment are unclear. The authors explored the effects of listening to music during extraction of the impacted mandibular third molar on the autonomic nervous system and the psychological state and hypothesized that listening to music would suppress sympathetic nervous activity and decrease anxiety. MATERIALS AND METHODS: In this prospective study, 40 patients scheduled for extraction of an impacted mandibular third molar were randomized into 2 groups: extraction without music (control group) and extraction while listening to music (music group). Heart rate variability was recorded during the experiment, and Modified Dental Anxiety Scale and State-Trait Anxiety Inventory (STAI) scores were recorded before and after the procedure. Descriptive and bivariate statistics were computed and the P value was set at .05. RESULTS: An increased low-to-high frequency ratio was observed in the control group during incision and flap reflection, bone removal, and separation of the tooth crown; the ratio was significantly decreased in the music group during these time points (P < .05). Compared with the control group, the music group had a significantly greater decrease in postoperative STAI State Anxiety scores from preoperative levels (P < .05). CONCLUSIONS: This study suggested that listening to music while undergoing extraction of the impacted mandibular third molar suppresses activity of the sympathetic nerves during incision, flap reflection, bone removal, and separation of the tooth crown and relieves anxiety after treatment. Future studies will focus on the mechanisms involved and methods to prevent the onset of systemic incidents.

Predictive Factors of Postoperative Blood Pressure Abnormalities Following a Minor-to-Moderate Surgery.

Myocardial ischemic events after non-cardiac surgery is still a serious problem, especially in older, high-risk patients. However, the prevalence and risk factors of blood pressure (BP) abnormalities, which may possibly lead to myocardial ischemic attack, have not been reported. Our aim is to elucidate predictive factors of postoperative BP abnormalities following a minor-to-moderate surgery, employing preoperative left ventricular diastolic function. Patients who underwent cardiac echocardiogram examination and received oral and maxillofacial surgery under general anesthesia were enrolled. The echocardiographic parameters of diastolic function were compared between patients who had postoperative BP abnormalities (hypertension-systolic blood pressure [SBP] ≥ 170 mmHg-or hypotension-SBP < 80 mmHg-episode) that required therapeutic interventions until 7 days after surgery and those who had no BP abnormalities. Of the 173 patients analyzed, 25 (14.4%) had BP abnormalities. BP abnormalities patients were older, having a larger proportion of diabetes mellitus, lower E/A ratio and e', and larger E/e' and left atrial dimension than those without BP abnormalities. Subanalyses revealed that the independent risk factors responsible for hypertension episodes (14 patients) were the mean e' (odd ratio [OR]: 0.434; 95% confidence interval [CI]: 0.229-0.824), diabetes mellitus (OR: 5.018; 95% CI: 1.030-24.436), SBP at hospitalization (OR: 1.099; 95% CI: 1.036-1.165), and operation time (hour; OR: 1.326; 95%CI: 1.109-1.586), while hypotension episodes (11 patients) were associated solely with operation time (OR: 1.206; 95% CI: 1.046-1.391). In conclusion, left ventricular diastolic dysfunction, increased insulin resistance, boosted SBP at hospitalization, and prolonged operation should be taken into consideration as risk factors of postoperative BP abnormalities, especially hypertension, following minor-to-moderate surgery.

Recovery of Endothelial Function after Minor-to-Moderate Surgery Is Impaired by Diabetes Mellitus, Obesity, Hyperuricemia and Sevoflurane-Based Anesthesia.

Endothelial dysfunction is observed in several cardiovascular diseases, where endothelium-dependent vasodilation is impaired by oxidative stress. However, the time course of endothelial function during the perioperative period of a minor-to-moderate surgery, and the effects of atherosclerotic risk factors and employed general anesthetics on recovery of endothelial function, are unknown. Endothelial function of 30 patients was evaluated as the reactive hyperemia index (RHI) of reactive hyperemia peripheral arterial tonometry. RHI was measured on day before surgery (control), immediately after surgery (Day 0), day after surgery (Day 1), and day 4 after surgery (Day 4) in patients with no functional limitations who were scheduled for oral and maxillofacial surgery of around 3 hours. Sevoflurane- or propofol-based anesthesia supplemented with an opioid analgesic remifentanil was employed. The control RHI was 2.26 ± 0.64. The RHI significantly decreased to the lowest level on Day 0 (1.52 ± 0.28), recovered on Day 1 (2.07 ± 0.58), and improved further on Day 4 (2.55 ± 0.83). Multiple linear regression analysis revealed that recovery of the RHI from Day 0 to Day 4 was impaired by diabetes mellitus (P = 0.0313), obesity (BMI ≥ 25; P = 0.0166), hyperuricemia (uric acid ≥ 6.0 mg/dL; P = 0.0416) and sevoflurane-based anesthesia (P = 0.0308). These findings suggest that endothelial function as evaluated by the RHI is severely suppressed on the day of a minor-to-moderate surgery, and that it improves until the 4th postoperative day on average. Recovery of endothelial function is impaired by diabetes mellitus, obesity, hyperuricemia, and sevoflurane-based anesthesia.

Anatomical variations of the torcular Herophili: macroscopic study and clinical aspects.

The anatomical variations of the confluence of sinuses were examined, focusing on the continuity of the superior sagittal sinus (SSS) and the transverse sinuses (TSs). In the 142 specimens studied, there were 72 symmetric cases (50.7%) and 70 asymmetric cases (49.3%). The symmetric group (no dominant type) was categorized into 34 cases of bifurcation (23.9%) and 38 cases of confluence (26.8%). The asymmetric group was categorized into 54 cases of the right-dominant type (38.0%) and 16 cases of the left-dominant type (11.3%). The right-dominant type was further categorized into 38 partially-communicating (26.8%) and 16 non-communicating types (11.3%). The left-dominant type was categorized into 11 partially-communicating (7.7%) and 5 non-communicating types (3.5%). In summary, the SSS asymmetrically drained into one TS in about half of the cases studied. The right-dominant type was about three to four times as common as the left-dominant type. The draining pattern shown by the asymmetric group could provoke intracranial hypertension due to unilateral jugular vein obstruction. In order to avoid this risk in cases of neck dissection, jugular vein catheterization, or hypercoagulopathy, preoperative evaluations of the dural sinus variations via MR venography, three-dimensional CT, or plain X-ray of the skull are recommended.

Effects of glucose-insulin infusion during major oral and maxillofacial surgery on postoperative complications and outcomes.

BACKGROUND: Secretion of hormones, which antagonize the action of insulin, is facilitated in response to surgery, and acute resistance to the action of insulin develops. Our aim is to elucidate the effects of intraoperative glycemic control by glucose-insulin (GI) infusion on postoperative complications and outcomes in major oral and maxillofacial surgery. FINDINGS: Thirty patients aged ≥ 60 years undergoing a radical operation of oral malignant tumors with tissue reconstruction (≥ 8 h) were analyzed. In the GI group, regular insulin was continuously applied with glucose-added acetate Ringer's solution (5-10 g glucose per 500 mL). Blood glucose was adjusted within the target concentration of 80-120 mg/dL. In the control group, combination of acetate Ringer's solution containing 1% (W/V) glucose and lactate Ringer's solution, which contains no glucose, was employed. Perioperative clinical parameters, incidence of hypoalbuminemia, and postoperative complications, i.e., surgical site infection, necrosis of a reconstructed flap, bacteremia, hypotension, or pneumonia, were compared. Both serum total protein and albumin concentrations (postoperative day 1 [Day1]) were higher in the GI group. The mean infusion rate of glucose during surgery (mg/kg/h) was independently associated with the decrease in both serum total protein and albumin concentrations from the control to Day1. No difference was found between the groups in the incidence of postoperative complications and the days required until discharge, except less incidence of hypoalbuminemia in the GI group. CONCLUSIONS: Application of additional glucose during major oral and maxillofacial surgery preserved serum albumin concentration. However, it did not lead to less postoperative complications and less days until discharge.

Anatomical variations of the recurrent artery of Heubner: number, origin, and course.

The clinical anatomy of the recurrent artery of Heubner (RAH) was examined, focusing on its number, origin, and course, in a large number of brain specimens. We studied 724 RAH in total from 357 brain specimens (714 hemispheres). In 98.74 % of 714 cases there were one or more RAHs, while it was absent in 1.26 % of cases. There was a single RAH in 96.22 % of cases, double in 2.38 % of cases, and triple in 0.14 % of cases. In this study, three origin types of the RAH were defined. We defined A1 and A2 segment of the anterior cerebral artery (ACA) as the artery from the origin of the ACA to the junction of the anterior communicating artery (AComA) and the artery from the junction of the AComA to the anterior border of the corpus callosum, respectively. In 76.2 % of 724 arteries, the RAH originated from the junction of the A1 and A2 segment of the ACA. In 16.3 %, the RAH originated from the A2 segment of the ACA. In 7.5 %, the RAH originated from the A1 segment of the ACA. The course of the RAH was superior to the A1 segment of the ACA in 30.1 % of 724 arteries, anterior in 62.2 %, and posterior in 7.7 %. It is of great importance for neurosurgeons to understand the detailed anatomical variations of the RAH before operating to prevent operative complications resulting in neurological deficits.

Dorsal and ventral parts of thalamic nucleus submedius project to different areas of rat orbitofrontal cortex: A single neuron-tracing study using virus vectors.

The rodent orbitofrontal cortex is involved in a variety of cognitive and behavioral functions that require thalamic input to be successfully expressed. Although the thalamic nucleus submedius (Sm) is a major source of afferents to the orbitofrontal cortex, thalamocortical projection from the Sm has not been fully elucidated. In the present study, we first divided the rat Sm into dorsal and ventral parts according to the distribution of vesicular glutamate transporter 2-immunoreactive varicosities, which were somatosensory afferents from the brain stem. Subsequently we investigated dendritic and axonal arborizations of individual dorsal and ventral Sm neurons by visualizing the processes with Sindbis virus vectors expressing membrane-targeted fluorescent proteins. The number of dendritic processes of ventral Sm neurons was greater than that of dorsal Sm neurons. In the cerebral cortex, all the reconstructed Sm neurons sent axons primarily to layers 2-5. Interestingly, dorsal Sm neurons formed a single axon arbor exclusively within the ventrolateral orbital area, whereas ventral Sm neurons made two axon arbors in the lateral orbital and ventral orbital areas simultaneously. The spread of each axon arbor was 500-1000 µm in diameter in the direction tangential to the cortical surface. These results indicate that the dorsal and ventral Sm comprise two distinct thalamocortical pathways. The dorsal Sm pathway relay somatosensory information to the ventrolateral orbital area and may be involved in emotional and aversive aspects of nociceptive information processing, whereas the ventral Sm pathway seems to co-activate distant orbitofrontal cortical areas, and may link their functions under certain circumstances.

Dorsal and Ventral Parts of Thalamic Nucleus Submedius Project to Different Areas of Rat Orbitofrontal Cortex: A Single Neuron-Tracing Study Using Virus Vectors.

The rodent orbitofrontal cortex is involved in a variety of cognitive and behavioral functions that require thalamic input to be successfully expressed. Although the thalamic nucleus submedius (Sm) is a major source of afferents to the orbitofrontal cortex, thalamocortical projection from the Sm has not been fully elucidated. In the present study, we first divided the rat Sm into dorsal and ventral parts according to the distribution of vesicular glutamate transporter 2-immunoreactive varicosities, which were somatosensory afferents from the brain stem. Subsequently we investigated dendritic and axonal arborizations of individual dorsal and ventral Sm neurons by visualizing the processes with Sindbis virus vectors expressing membrane-targeted fluorescent proteins. The number of dendritic processes of ventral Sm neurons was greater than that of dorsal Sm neurons. In the cerebral cortex, all the reconstructed Sm neurons sent axons primarily to layers 2-5. Interestingly, dorsal Sm neurons formed a single axon arbor exclusively within the ventrolateral orbital area, whereas ventral Sm neurons made two axon arbors in the lateral orbital and ventral orbital areas simultaneously. The spread of each axon arbor was 500-1000 µm in diameter in the direction tangential to the cortical surface. These results indicate that the dorsal and ventral Sm comprise two distinct thalamocortical pathways. The dorsal Sm pathway relay somatosensory information to the ventrolateral orbital area and may be involved in emotional and aversive aspects of nociceptive information processing, whereas the ventral Sm pathway seems to co-activate distant orbitofrontal cortical areas, and may link their functions under certain circumstances. This article is protected by copyright. All rights reserved.

Individual mediodorsal thalamic neurons project to multiple areas of the rat prefrontal cortex: A single neuron-tracing study using virus vectors.

The prefrontal cortex has an important role in a variety of cognitive and executive processes, and is generally defined by its reciprocal connections with the mediodorsal thalamic nucleus (MD). The rat MD is mainly subdivided into three segments, the medial (MDm), central (MDc), and lateral (MDl) divisions, on the basis of the cytoarchitecture and chemoarchitecture. The MD segments are known to topographically project to multiple prefrontal areas at the population level: the MDm mainly to the prelimbic, infralimbic, and agranular insular areas; the MDc to the orbital and agranular insular areas; and the MDl to the prelimbic and anterior cingulate areas. However, it is unknown whether individual MD neurons project to single or multiple prefrontal cortical areas. In the present study, we visualized individual MD neurons with Sindbis virus vectors, and reconstructed whole structures of MD neurons. While the main cortical projection targets of MDm, MDc, and MDl neurons were generally consistent with those of previous results, it was found that individual MD neurons sent their axon fibers to multiple prefrontal areas, and displayed various projection patterns in the target areas. Furthermore, the axons of single MD neurons were not homogeneously spread, but were rather distributed to form patchy axon arbors approximately 1 mm in diameter. The multiple-area projections and patchy axon arbors of single MD neurons might be able to coactivate cortical neuron groups in distant prefrontal areas simultaneously. Furthermore, considerable heterogeneity of the projection patterns is likely, to recruit the different sets of cortical neurons, and thus contributes to a variety of prefrontal functions. J. Comp. Neurol. 525:166-185, 2017. © 2016 Wiley Periodicals, Inc.

Associations between blood pressure responses to acute stress and impaired renal function and serum uric acid level.

The study aimed to examine correlations between blood pressure (BP) responses to direct laryngoscopy and tracheal intubation and parameters of renal function, serum uric acid (SUA) level, and mean preoperative BP. Fifty-four patients (≥ 40 years) who were scheduled for oral surgery were analyzed. General anesthesia was induced by the rapid sequence method without opioid analgesics. Systolic and diastolic BP (SBP, DBP) in the operation room were measured when an electrocardiogram, a BP cuff, and a pulse oximetry probe were attached to the patients (T1) and immediately after the trachea was intubated (T2). The ΔSBP was defined as the difference between SBP at T2 and T1. The increasing rate of SBP (ΔSBPr) was defined as ΔSBP/SBP at T1. SBP at T2 was associated with increasing age (R = 0.44), serum creatinine (R = 0.32), SUA (R = 0.30), mean preoperative SBP and DBP (R = 0.54 and 0.37, respectively), and reduced estimated glomerular filtration rate (eGFR) (R = -0.44). Serum creatinine and SUA were positively associated, and eGFR was negatively associated with ΔSBP (R = 0.36, 0.34, and -0.29) and ΔSBPr (R = 0.39, 0.37, and -0.29). Multivariate regression analysis revealed that age and mean preoperative SBP was independently associated with SBP at T2, and serum creatinine was independently associated with ΔSBP and ΔSBPr. These findings suggested that elevated serum creatinine level, as well as elevated preoperative BP level, was associated with enhanced BP responses to acute stress in middle-aged to elderly patients.

Ventral medial nucleus neurons send thalamocortical afferents more widely and more preferentially to layer 1 than neurons of the ventral anterior-ventral lateral nuclear complex in the rat.

Not only inhibitory afferent-dominant zone (IZ) of the ventral anterior-ventral lateral thalamic complex (VA-VL) but also the ventral medial nucleus (VM) is known to receive strong inputs from the basal ganglia and send axons to motor areas. We previously reported differences in axonal arborization between IZ neurons and the other VA-VL neurons in rats by single-neuron tracing with viral vectors. In the present study, the axonal arborization of single VM neurons was visualized by the same method, and compared with that of IZ neurons. VM neurons formed fewer axon collaterals in the striatum, but sent axon fibers more widely and more preferentially (79% of fibers) to layer 1 of cortical areas than IZ neurons. Furthermore, the VM seemed to contain at least 2 types of neurons; a major population of VM neurons sent axon fibers principally to motor-associated areas as VA-VL neurons did, and the other population projected mainly to orbital or cingulate areas. Although both VM and IZ neurons receive strong basal ganglia inputs, these results suggest that VM neurons, at a single neuron level, innervate the apical dendrites of cortical pyramidal neurons more intensely and more widely than IZ neurons.

Associations between the autonomic nervous system and the second derivative of the finger photoplethysmogram indices.

AIM: The indices of the second derivative of the finger photoplethysmogram(SDPTG) denote stiffness of large arteries, peripheral vascular resistance and vascular aging. However, the association between the autonomic nervous activity and the SDPTG indices has not yet been elucidated. METHODS: The SDPTG and heart rate variability(HRV) were consecutively measured in the sitting position on the day before surgery in 168 patients 18-89 years of age. The relationships between the SDPTG indices(b/a, c/a, d/a and e/a) and HRV indices(power spectral analysis and time domain analysis parameters) were analyzed. The relationships between c/a and atherosclerosis-based conditions and risk factors for atherosclerosis were also evaluated. RESULTS: The SDPTG index b/a was negatively associated and the d/a index was positively associated with the low-frequency(LF)(R=-0.44 and 0.42, respectively) and high-frequency(HF) components(R=-0.31 and 0.35, respectively). The SDPTG index c/a was also positively associated with the LF(R=0.40) and HF(R=0.44) components. A multivariate regression analysis showed that the LF, HF and heart rate were independent determinants of the c/a. Furthermore, the c/a values were significantly lower in the patients with hypertension, diabetes mellitus and hyperlipidemia than in those without these diseases, and a reduced c/a was significantly associated with increased serum triglyceride and total cholesterol concentrations. CONCLUSIONS: These findings suggest that a decrease in c/a is associated with a reduced baroreflex response of the peripheral vasomotor activity and a decreased cardiac parasympathetic activity. Furthermore, a decrease in c/a was found to be associated with atherosclerosis-based conditions, such as hypertension, diabetes mellitus and hyperlipidemia.