Increasing climacteric symptoms in untreated perimenopausal Finnish women: a 10-year cohort study.

OBJECTIVE: This study aimed to examine changes over a 10-year period in experiencing climacteric symptoms and their associations with sociodemographic and health-related background factors in a birth cohort of Finnish women who have never used menopausal hormone therapy (MHT). METHODS: This nationwide population-based follow-up study consists of 1491 women who during the follow-up period moved from the age group 42-46 years to the age group 52-56 years. The experience of climacteric symptoms was assessed by 12 symptoms commonly associated with the climacterium. The data were analyzed using statistical techniques. RESULTS: Both the intensity, expressed as a symptom score of four symptoms associated with a decrease in estrogen production (sweating, hot flushes, vaginal dryness, sleeping problems), and the prevalence of the five most common symptoms (sweating, hot flushes, sleeping problems, lack of sexual desire, depressive symptoms) increased clearly during the follow-up period. The examined sociodemographic and health-related variables did not explain the changes in experiencing the symptoms. CONCLUSIONS: The results of this study can be considered in primary and occupational health care and in gynecological settings when working with symptomatic women or women with hidden climacteric problems and carrying out health promotion and counseling for them.

Is excessive daytime sleepiness a separate manifestation in Parkinson's disease?

BACKGROUND: Excessive daytime sleepiness (EDS) is common in Parkinson's disease (PD), but its role and relation to other PD features is less well understood. OBJECTIVE: To investigate potential predictors of EDS in PD and to explore how EDS relates to other motor and non-motor PD features. METHODS: 118 consecutive persons with PD (54% men; mean age, 64) were assessed regarding EDS using the Epworth Sleepiness Scale (ESS) and a range of motor and non-motor symptoms. Variables significantly associated with ESS scores in bivariate analyses were used in multiple regression analyses with ESS scores as the dependent variable. Principal component analysis (PCA) was conducted to explore the interrelationships between ESS scores and other motor and non-motor PD aspects. RESULTS: Among 114 persons with complete ESS data, significant independent associations were found between ESS scores and axial/postural/gait impairment, depressive symptoms, and pain (R2, 0.199). ESS scores did not load significantly together with any other PD features in the PCA. CONCLUSIONS: Only a limited proportion of the variation in EDS could be accounted for by other symptoms, and EDS did not cluster together with any other PD features in PCAs. This suggests that EDS is a separate manifestation differing from, for example, poor sleep quality and fatigue.

Brainstem and thalamic projections from a craniovascular sensory nervous centre in the rostral cervical spinal dorsal horn of rats.

To examine the ascending projections from the headache-related trigeminocervical complex in rats, biotinylated dextran amine (BDA) was injected into the ventrolateral dorsal horn of segments C1 and C2, a region previously demonstrated to receive input from sensory nerves in cranial blood vessels. Following injections into laminae I-II, BDA-labelled terminations were found bilaterally in several nuclei in the pons and the midbrain, including the pontine reticular nucleus, the parabrachial nuclei, the cuneiform nucleus and the periaqueductal grey. In the diencephalon, terminations were confined to the contralateral side and evident foremost in the posterior nuclear group, especially its triangular part, and in the ventral posteromedial nucleus. Following injections extending through laminae I-IV, anterograde labelling was more extensive. Some of the above regions are likely to be involved in the central processing of noxious signals of craniovascular origin and therefore putatively involved in mechanisms associated with primary headaches.

Auricular Acupuncture and Cognitive Behavioural Therapy for Insomnia: A Randomised Controlled Study.

Objective. The most effective nonpharmacological treatment for insomnia disorder is cognitive behavioural therapy-insomnia (CBT-i). However CBT-i may not suit everyone. Auricular acupuncture (AA) is a complementary treatment. Studies show that it may alleviate insomnia symptoms. The aim of this randomised controlled study was to compare treatment effects of AA with CBT-i and evaluate symptoms of insomnia severity, anxiety, and depression. Method. Fifty-nine participants, mean age 60.5 years (SD 9.4), with insomnia disorder were randomised to group treatment with AA or CBT-i. Self-report questionnaires, the Insomnia Severity Index (ISI), Dysfunctional Beliefs and Attitudes about Sleep scale (DBAS-16), Epworth Sleepiness Scale (ESS), and Hospital Anxiety and Depression scale (HAD), were collected at baseline, after treatment, and at 6-month follow-up. A series of linear mixed models were performed to examine treatment effect over time between and within the groups. Results. Significant between-group improvements were seen in favour of CBT-i in ISI after treatment and at the 6-month follow-up and in DBAS-16 after treatment. Both groups showed significant within-group postintervention improvements in ISI, and these changes were maintained six months later. The CBT-i group also showed a significant reduction in DBAS-16 after treatment and six months later. Conclusions. Compared to CBT-i, AA, as offered in this study, cannot be considered an effective stand-alone treatment for insomnia disorder. The trial is registered with ClinicalTrials.gov NCT01765959.

Characteristics associated with initiation of hormone replacement therapy among Finnish women: A register-linkage study.

OBJECTIVE: To investigate which patient characteristics are associated with the initiation of hormone replacement therapy (HRT) in a cohort of Finnish women. STUDY DESIGN: Responses to postal questionnaires distributed to a nationwide, randomly selected cohort of women in 1998, 2000, 2003, 2005 and 2010 were analyzed. The cohort members were aged 40-44 years at the beginning of the study. Information on hormone replacement therapy was received from the national prescription register. Women who started taking HRT between January 1, 1999 and December 31, 2011 were included and previous users were excluded from the analysis. MAIN OUTCOME MEASURES: Initiation of HRT was the main outcome measure. The following explanatory factors for predicting the use of HRT were examined: sociodemographic factors, personality, health behavior, physiological and mental symptoms, chronic diseases and use of psychopharmaceuticals. The associations between starting HRT and the explanatory factors were analyzed with single-predictor and multi-predictor logistic regression models. RESULTS: Factors predicting that a woman would start taking HRT were: living with a partner, weak sense of coherence, BMI less than 30kg/m(2), heavy or moderate alcohol use, symptoms of hyperactivity of the sympathetic nervous system, climacteric symptoms and use of psychopharmaceuticals. CONCLUSIONS: Women with a good sense of coherence can cope with climacteric symptoms without resorting to HRT. Clinicians need to bear in mind the burden of menopausal symptoms on a woman's personal and working life when HRT is being considered.

Quality of life in adults with growth hormone (GH) deficiency: response to treatment with recombinant human GH in a placebo-controlled 21-month trial.

We examined the effect of GH supplementation on the psychological capacity and sense of well-being in 36 patients with adult-onset GH deficiency (GHD). Recombinant human GH was given in a 21-month cross-over, double blind trial, and quality of life was assessed by using three self-rating questionnaires: the Hopkins Symptom Check List (HSCL), the Nottingham Health Profile (NHP), and the Psychological General Well-Being index. In addition, at the final examination the spouses completed a short questionnaire concerning their partner. Before treatment, the patients had lowered quality of life as determined by the HSCL and NHP inventories, and a correlation between the duration of GHD and the reported symptoms was observed. Upon treatment, the HSCL score was lower (better) after placebo administration (mean +/- SD, 84 +/- 21.3) than at baseline (89 +/- 18.9; P = NS) and fell to 80.2 +/- 18.5 (P < 0.001) when active drug was given. The subscales regarding anxiety, fearfulness, and cognition were the most sensitive. It was apparent that the effect determined after GH therapy in part was due to a placebo effect. With NHP, the dimensions of energy and emotions responded most to treatment. Further, the spouses observed their partners to be improved in several aspects of mood and behavior (P < 0.05 to P < 0.0001) when active drug was given. The data thus demonstrate that GH, which is known to have multiple somatic effects, produces an improvement in the quality of life of adults with GHD.

Brain networks affected by synchronized sleep visualized by positron emission tomography.

Nineteen lightly sleep-deprived healthy volunteers were examined with H2(15)O and positron emission tomography (PET). Scanning was performed during wakefulness and after the subjects had fallen asleep. Sleep stage was graded retrospectively from electroencephalogram (EEG) recordings, and scans were divided into two groups: wakefulness or synchronized sleep. Global flow was quantified, revealing no difference between sleep and wakefulness. A pixel-by-pixel-blocked one-way analysis of variance (ANOVA) was performed after correcting for differences in anatomy and global flow. The sum of squares of the z-score distribution showed a highly significant (P < 0.00001) omnibus difference between sleep and wakefulness. The z-score images indicated decreased flow in the thalamus and the frontal and parietal association cortices and increased flow in the cerebellum during sleep. A principal component (PC) analysis was performed on data after correction for global flow and block effects, and a multivariate analysis of variance (MANOVA) on all PC scores revealed significant (P = 0.00004) differences between sleep and wakefulness. Principal component's 2 and 5 correlated to sleep and revealed distinct networks consisting of PC 2, cerebellum and frontal and parietal association cortices, and PC 5, thalamus.

GABA-immunoreactive neurons and terminals in the lateral cervical nucleus of the cat.

Previous findings have indicated the presence of local circuit neurons in the lateral cervical nucleus (LCN). An immunohistochemical study with gamma-aminobutyric acid (GABA) antiserum was therefore performed both to investigate whether GABA-immunoreactive neurons are present in the LCN, and if so, to compare their characteristics with those previously assigned to probable internuncial neurons in the nucleus. The fine structure and synaptology of GABA-positive boutons in the LCN were also studied. Transversely cut sections from the upper cervical spinal cord of three cats were processed for GABA immunohistochemistry with the free-floating PAP technique. On light microscopic examination immunoreactive neurons were observed within the ventromedial half of the LCN. Their total number was estimated to be 42.5 +/- 11.7 in the entire LCN on one side of the cervical spinal cord, but this may have been an underestimation, as the penetration by the antisera was limited. The labeled neurons were small and had a relatively large nucleus and a low bouton covering ratio. In their number, localization, and ultrastructural appearance the GABA-positive neurons closely resembled the population of neurons previously suggested to be local circuit neurons. Immunoreactive bouton-sized puncta were scattered throughout the LCN. Ultrastructural examination showed labeled terminals with a mean sectional area of 0.85 micron 2 and a relatively high density of synaptic vesicles. The vast majority of GABA-positive terminals were in contact with dendrites and only a minority had synaptic contact with cell bodies. No axoaxonal synapses were observed. The GABA-positive boutons probably derive at least partly from the observed GABA-positive neurons, but there is also a possibility of extrinsic GABAergic input.

Compartmentation of glutamate and glutamine in the lateral cervical nucleus: further evidence for glutamate as a spinocervical tract neurotransmitter.

Previous observations indicate that spinocervical tract terminals contain relatively high levels of glutamate. To examine whether these high glutamate levels are likely to represent a neurotransmitter pool or an elevated metabolic pool, the distributions of glutamate- and glutamine-like immunoreactivities were examined in adjacent immunogold-labeled sections of the lateral cervical nucleus. Spinocervical tract terminals were identified by anterograde transport of horseradish peroxidase and wheat germ agglutinin-horseradish peroxidase conjugate from the spinal cord. Spinocervical tract terminals were found to contain significantly higher levels of glutamate-like immunoreactivity than other examined tissue compartments (large neuronal cell bodies, terminals with pleomorphic vesicles, astrocytes, and average tissue level). In contrast, the highest levels of glutamine-like immunoreactivity were detected in astrocytes. The different analyzed tissue elements formed three groups with respect to glutamate:glutamine ratios: one high ratio group including spinocervical tract terminals, a second group with intermediate ratios consisting of neuronal cell bodies and terminals containing pleomorphic synaptic vesicles, and a third low ratio group including astrocytes. Our findings indicate the presence of a compartmentation of glutamate and glutamine in the lateral cervical nucleus, similar to that postulated in biochemical studies of the central nervous system. The results also show that spinocervical tract terminals have high glutamate: glutamine ratios, similar to those previously observed in putative glutamatergic terminals in the cerebellar cortex. Thus, spinocervical tract terminals display biochemical characteristics that would be expected of glutamatergic terminals and the present findings therefore provide further evidence for glutamate as a spinocervical tract neurotransmitter.

Substance P-like immunoreactivity in the lateral cervical nucleus of the owl monkey (Aotus trivirgatus): a comparison with the cat and rat.

The location of substance P (SP) in the lateral cervical nucleus (LCN) of monkeys (Aotus trivirgatus), cats, and rats was investigated with immunohistochemical methods. Light microscopic analysis showed that SP-positive fibers and terminals are evenly distributed throughout the LCN of the monkey and rat, whereas the SP labeling in the LCN of the cat is concentrated in the medial part of the nucleus, with only very sparse labeling in the lateral part. Electron microscopic examination of the monkey LCN revealed the presence of SP-like immunoreactivity within terminal boutons and unmyelinated axons. The SP-positive boutons are in synaptic contact with dendrites and, occasionally, cell bodies; they contain densely packed, clear, round synaptic vesicles, as well as dense-core vesicles. The distribution of SP-like immunoreactivity in the LCN of monkeys, cats, and rats is similar to that of nociceptive-responsive neurons demonstrated in electrophysiological experiments. The possible role of the SP-containing fibers in the transmission of nociceptive information through the LCN is discussed.

GABA-immunoreactive neurons and terminals in the lateral cervical nucleus of the cynomolgus monkey.

An antiserum against the inhibitory transmitter substance gamma-aminobutyric acid (GABA) was used to investigate the distribution of GABAergic nerve terminals and cell bodies in the lateral cervical nucleus (LCN) of the cynomolgus monkey. Light microscopic immunohistochemistry demonstrated GABA-immunoreactive puncta, suggestive of nerve terminals, scattered throughout the LCN. The terminal-like profiles are often present along the somata of unlabeled neurons, but most are located in the neuropil. GABA-immunoreactive neurons are present in the LCN, but constitute a very small number of the LCN neurons. Electron microscopy showed that the GABA-positive neurons are small with a relatively large nucleus. They are contacted by few somatic boutons. Numerous GABA-immunoreactive terminals containing densely packed round to oval synaptic vesicles were also found. Most GABA-positive terminals make synaptic contact with dendrites, but synapses with cell bodies are also present. Synaptic contacts between labeled and unlabeled terminals were not observed. Some GABA-positive terminals make contact with GABA-positive neurons. The present findings suggest that GABA is a major inhibitory transmitter substance in the LCN of the monkey. However, in comparison with other somatosensory relay nuclei, there are few GABA-immunoreactive neurons in the LCN. This may imply that the GABA-positive neurons branch extensively in the LCN or that an extrinsic source of GABAergic input exists.

Serotoninergic innervation of the dorsal column nuclei and its relation to cytoarchitectonic subdivisions: an immunohistochemical study in cats and monkeys (Aotus trivirgatus).

The serotoninergic innervation of the dorsal column nuclei (DCN) was investigated in cats and owl monkeys (Aotus trivirgatus) with immunohistochemical methods. A dense network of serotonin-immunoreactive fibers was present in the reticular regions of DCN in cats, and in the pars triangularis of the cuneate nucleus and the peripheral and caudal regions of the gracile nucleus in owl monkeys. The cat's cluster regions and the monkey's rotund regions were more sparsely innervated. Electron microscopic examination showed that the labeled fibers were thin and unmyelinated. Vesicle-containing, terminal-like structures were small. They were in contact with dendrites, other terminals and cell bodies, but synapses were rare. The results demonstrate that the serotoninergic projection to the DCN in both cats and owl monkeys is heterogeneously distributed in a pattern that is faithfully related to the cytoarchitectonic subdivisions of the DCN. The densely innervated reticular regions in the DCN of cats and the corresponding regions in monkeys are predominantly involved in the processing of sensory information to the cerebellum, either directly, or indirectly through projections to the inferior olive, pontine gray, tectum, pretectum, red nucleus, or zona incerta. Thus, the present findings suggest that the serotoninergic innervation of the DCN is primarily related to the DCN's involvement in motor functions.

Substance P-like and serotonin-like immunoreactivity in the lateral cervical nucleus of the raccoon.

The distribution of substance P and serotonin in the lateral cervical nucleus (LCN) of the raccoon was examined by light microscopic immunohistochemistry. Substance P-immunoreactive fibers were found to be clustered in the ventromedial part of the LCN, whereas only few such fibers appeared in the dorsolateral part of the nucleus. This organization is closely similar to that previously observed in the cat, and provides further evidence for an anatomic and functional segregation along the transverse axis of the LCN in carnivores. In some sections, substance P-positive fibers were found primarily in areas of the ventromedial LCN containing small neurons, indicating that such fibers may be involved in functions of the LCN associated with nociceptive projection neurons and/or local circuit neurons. The raccoon LCN also received a relatively sparse innervation of serotonin-positive fibers that were distributed throughout the nucleus, an organization similar to that previously observed in the cat. The functional role of the serotonergic fibers is unclear. However, their presence suggests that descending influences on transmission in the spinocervicothalamic pathway, in addition to the well-documented descending control of spinocervical tract neurons, may be present also at the level of the LCN.

Postnatal development of the feline lateral cervical nucleus: I. A quantitative light and electron microscopic study.

With the aim of obtaining some basic information for future developmental studies, the lateral cervical nucleus (LCN) was investigated in 32 kittens of different ages by electron microscopic and stereologic methods. Corresponding light microscopic measurements of neuronal and nuclear profiles and of the total LCN volume were also performed. The total LCN volume increased sixfold between the ages of 12 hours and 120 days, the most rapid increase occurring during the first month. The neuronal size was fairly constant up to the age of 9 days, whereafter it showed greater variation. The mean profile area increased rapidly during the second week and then more slowly. The relative volume of boutons increased significantly between birth and the age of 34 days and then decreased slightly up to 120 days postnatally. The total bouton volume showed a steady increase, which was most pronounced between the ages of 9 and 34 days. The relative dendritic volume decreased during the 120 days of observation, whereas the total volume of dendrites increased up to the age of 92 days and then decreased. The total volume of glial cells increased during the 120-day observation period, as did both the relative and total volumes of myelinated axons. The changes in the relative volumes of mitochondria in boutons and dendrites were very similar, with increases that were most marked between the ages of 9 and 34 days and between 92 and 120 days.

Lamina I spinocervical tract terminations in the medial part of the lateral cervical nucleus in the cat.

The terminations of spinocervical tract fibers in the lateral cervical nucleus (LCN) of the cat were examined with anterogradely transported Phaseolus vulgaris leucoagglutinin (PHA-L) in order to analyze their organization relative to the most medial part and the main body (the lateral two-thirds) of the LCN, which have differential projections and physiological characteristics. Iontophoretic injections of PHA-L in laminae I-V of the spinal dorsal horn yielded dense labeling in somatotopically appropriate regions of the main body of the LCN, and, as seen previously with horseradish peroxidase, additional terminations were present in the medial LCN after injections at either cervical or lumbar spinal levels. The morphological characteristics of the PHA-L labeling in these two parts of the LCN were different. Terminations in the lateral LCN consisted of dense clusters of thick fibers bearing large numbers of boutons. The terminal axons in the medial part of the LCN displayed a reticulated network of longitudinally oriented, fine fibers with well-spaced varicosities. Some of the fine fibers in the medial LCN appeared to be collaterals of thicker fibers that terminated in the lateral LCN. Injections of PHA-L that were restricted to lamina I resulted in terminal labeling only in the medial LCN. The labeling was more sparse than that observed in the medial LCN after larger dorsal horn injections but displayed the same morphological characteristics. Lamina I terminations were seen in the medial LCN after cervical or lumbar injections on both the ipsilateral and contralateral sides. The PHA-L observations were corroborated by the presence of many retrogradely labeled lamina I cells at both cervical and lumbar spinal levels, following injections of cholera toxin subunit b or rhodamine-labeled microspheres in the medial LCN. In addition, double-immunofluorescent labeling for PHA-L and substance P was performed in a few cases, since substance P immunoreactivity is present in fibers in the medial LCN and also in cell bodies in lamina I; however, very few spinocervical fibers displayed immunoreactivity for both antigens. These observations indicate that the medial part of the LCN receives input from lamina I neurons, and probably from lamina III-V neurons as well, at cervical and lumbar spinal levels. The lamina I input to the medial LCN provides a basis for the small population of nociceptive neurons that differentiate the medial LCN. The lamina I input could also be responsible for the general inhibition of lateral LCN neurons by wide-field noxious stimulation, via activation of GABAergic interneurons in the medial LCN.(ABSTRACT TRUNCATED AT 400 WORDS)

Quantitative analysis of immunogold labeling indicates low levels and non-vesicular localization of L-aspartate in rat primary afferent terminals.

The role of L-aspartate as an excitatory neurotransmitter in primary afferent synapses in the spinal cord dorsal horn is disputed. To further investigate this issue, we examined the presence of aspartate-like immunoreactivity in primary afferent nerve terminals and other tissue components of the dorsal horn. We also examined the relationship between aspartate and glutamate immunogold labeling density and the density of synaptic vesicles in primary afferent terminals and presumed inhibitory terminals forming symmetric synapses. Weak aspartate immunosignals, similar to or lower than those displayed by presumed inhibitory terminals, were detected in both C-fiber primary afferent terminals in lamina II (dense sinusoid axon terminals, identified by morphological criteria) and in A-fiber primary afferent terminals in laminae III-IV (identified with anterograde transport of choleragenoid-horseradish peroxidase conjugate). The aspartate immunogold signal in primary afferent terminals was only about one-fourth of that in deep dorsal horn neuronal cell bodies. Further, whereas significant positive correlations were evident between synaptic vesicle density and glutamate immunogold labeling density in both A- and C-fiber primary afferent terminals, none of the examined terminal populations displayed a significant correlation between synaptic vesicle density and aspartate immunogold labeling density. Thus, our results indicate relatively low levels and a non-vesicular localization of aspartate in primary afferent terminals. It is therefore suggested that aspartate, rather than being a primary afferent neurotransmitter, serves a role in the intermediary metabolism in primary afferent terminals.

Central projections of sensory innervation of the rat superior sagittal sinus.

The central projections of the rat superior sagittal sinus (SSS) sensory innervation were studied by transganglionic tract tracing techniques. Cholera toxin subunit b (CTb) or wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) was applied on the overlying dura of the SSS and labeled terminations in the brainstem and cervical spinal cord were examined under the light microscope. Labeled cell bodies were seen bilaterally in the trigeminal ganglia and in the C2 dorsal root ganglia following both CTb and WGA-HRP applications. In the brainstem, labeled terminations were mainly found in the caudal and interpolar parts of the spinal trigeminal nucleus. In the CTb cases, terminations were also found in the dorsolateral part of the cuneate nucleus. In the spinal cord, labeled terminations were primarily located in the most ventrolateral part of the C1-C3 spinal dorsal horns on both sides. WGA-HRP labeled terminations were mainly located in laminae I and II, whereas CTb-labeled terminations located in laminae III and IV. These results indicate that the sensory information from the SSS is transmitted through both trigeminal and cervical spinal nerve branches to a primary sensory nervous center that extends from the C3 dorsal horn until to the interpolar part of the spinal trigeminal nucleus.

Evidence for vesicular storage of glutamate in primary afferent terminals.

The correlation between the density of gold particles signalling fixed glutamate and the density of synaptic vesicles was examined in primary afferent terminals in the rat dorsal horn. Statistically significant positive correlations between these parameters were found in lamina I and III-V primary afferent terminals, identified through axonal transport of choleragenoid-horseradish peroxidase conjugate, and in lamina II dense sinusoid axon terminals of presumed thin calibre primary afferent origin. Profiles containing pleomorphic synaptic vesicles displayed negative or statistically insignificant correlations between the density of synaptic vesicles and that of gold particles. These observations indicate that primary afferent terminals store glutamate in synaptic vesicles and provide further evidence for a role of glutamate as a primary afferent neurotransmitter.

The cervicothalamic tract terminates in Cat301-sparse regions of the cat VPL.

The termination pattern of the cervicothalamic tract (CTI), labelled with anterogradely transported WGA-HRP, was compared with the immunolabelling pattern obtained with the monoclonal antibody Cat301 in adjacent sections through the ventral posterolateral nucleus (VPL). CTT terminations are located in peripheral parts of the medial and lateral parts of the VPL (VPLm and VPL1), being more extensive in the caudal than in the rostral parts of the subnuclei, and in the dorsal part of VPL1 and dorsolateral part of VPLm, regions that are all sparse in CAt301 immunoreactivity. Central regions of the VPL with dense Cat301 immunolabelling contain only very sparse CTT termination. Thus, our findings show that the CTT innervates a compartment of the VPL that is characterized by sparse Cat301 immunoreactivity.

Morphological features of cat cervicothalamic tract terminations in different target regions.

Using biotinylated dextran amine to label cervicothalamic tract terminations of cats, three types of terminal arrangements were recognized. The ventral posterior lateral nucleus contains the largest proportion of the cervicothalamic tract terminals (79%) and most (72%) of these are type I terminals (form compact clusters of 5-30 boutons). In contrast, type II (form less compact clusters of 3-10 boutons) and type III (widely spaced boutons along thin axons) terminals dominate in the medial nucleus of the posterior complex (78%) and in the ventral periphery of the ventrobasal complex (86%). In the magnocellular medial geniculate nucleus, type I terminals (38%) are found close to medially located clusters of Cat-301 immunoreactive neurons, whereas type II and type III terminals locate in the surrounding Cat-301-negative regions. These findings indicate a high degree of synaptic security in the transmission between cervicothalamic tract fibers and neurons in the ventral posterior lateral nucleus and highlight the role of this nucleus in faithful transmission of cervicothalamic tract input to the cerebral cortex. Also, the Cat-301-positive neurons in the magnocellular medial geniculate nucleus may faithfully transmit cervicothalamic tract signals. The domination of type II and type III terminals in the medial nucleus of the posterior complex and in the ventral periphery of the ventrobasal complex indicates a more divergent cervicothalamic input to these regions, in line with the large receptive fields and multimodal responses of neurons in the posterior complex.