The pterygopalatine ganglion, palatine nerves and vessels: dissection and pathway / El ganglio pterigopalatino, nervios palatinos y vasos: disección y trayecto

SUMMARY: Background and Objectives: The palatine nerves and vessels cross the pterygopalatine fossa, the palatine canals, the palatine foramina and the submucosal space, at the level of the hard palate and the palatine recess of the maxillary sinus. Their trajectory is long, complicated and difficult to highlight on a single dissection piece. In the literature that we studied, we did not find clear images that fully highlight the real configuration of the pterygopalatine ganglion and nerves and of the palatine vessels. Our aim was to provide a clear and representative dissection of the pterygopalatine ganglion and of the palatine neurovascular bundle throughout its pathway in a simple, coherent and useful presentation for the practitioners interested in the regional pathology. We resected the posterior and inferomedial osseous walls of the maxillary sinus and highlighted the neurovascular structures in the pterygopalatine fossa and the wall of the maxillary sinus. We photographed the dissection fields and detailed the important relations. The images that we obtained are clear, simple and easy to interpret and use. We successfully highlighted the aspect and the main relations of the pterygopalatine ganglion and the pathway and distribution of the palatine nerves and vessels, from their origin to the terminal plexuses. There is a broad spectrum of clinical procedures or situations that require a proper knowledge and understanding of the anatomical pathway and relations of the palatine neurovascular elements. This includes the various types of regional anesthesia, tumor resection surgery, flaps of the palatine mucosa, the LeFort osteotomy etc. Demonstration of the pterygopalatine ganglion and its relations is useful in endoscopic interventions at the level of the pterygopalatine fossa.

RESUMEN: Los nervios y vasos palatinos atraviesan la fosa pterigopalatina, además de los canales palatinos, los forámenes palatinos y el espacio submucoso a nivel del paladar duro y el receso palatino del seno maxilar. Su trayectoria es larga, complicada y difícil de destacar en una sola pieza de disección. En la literatura que estudiamos, no encontramos imágenes claras que resalten completamente la configuración real del ganglio y los nervios pterigopalatinos y de los vasos palatinos. Nuestro objetivo fue proporcionar una disección clara y representativa del ganglio pterigopalatino y del haz neurovascular palatino a lo largo de su trayecto en una presentación simple, coherente y útil para los médicos interesados en la patología regional. Resecamos las paredes óseas posterior e inferomedial del seno maxilar y resaltamos las estructuras neurovasculares en la fosa pterigopalatina y la pared del seno maxilar. Fotografiamos los campos de disección y detallamos las relaciones importantes. Las imágenes que obtuvimos son claras, sencillas y de fácil interpretación. Resaltamos con éxito el aspecto y las principales relaciones del ganglio pterigopalatino y el trayecto y distribución de los nervios y vasos palatinos, desde su origen hasta los plexos terminales. En conclusion, existe un amplio espectro de procedimientos o situaciones clínicas que requieren un adecuado conocimiento y comprensión del trayecto anatómico y las relaciones de los elementos neurovasculares palatinos. Esto incluye los distintos tipos de anestesia regional, cirugía de resección tumoral, colgajos de mucosa palatina, osteotomía de LeFort, etc. La demostración del ganglio pterigopalatino y sus relaciones es útil en intervenciones endoscópicas a nivel de la fosa pterigopalatina.

Clinical Anatomy of Blockade of the Pterygopalatine Ganglion: Literature Review and Pictorial Tour Using Cadaveric Images.

Pterygopalatine ganglion block (sphenopalatine ganglion block) is a well-known procedure for treating cluster headache and for relieving cancer pain. In this review, the history and anatomy of the pterygopalatine ganglion are discussed, and images, including computed tomography and endoscopy, are presented to improve understanding of the clinical anatomy of the ganglion regarding the block procedure.

Patterns of innervation of the lacrimal gland with clinical application.

Parasympathetic stimulation of the lacrimal gland is responsible for tear production, and this innervation originates from fibers conveyed in the facial nerve. After synapse in the pterygopalatine ganglion, postsynaptic parasympathetic fibers travel within the zygomatic and zygomaticotemporal nerves (ZTN) into the orbit. As described in most anatomy texts, ZTN communicates with the lacrimal nerve (LN) posterior to the gland and then secretomotor fibers enter the gland. This study was performed to gain a better understanding of the innervation of the lacrimal gland. Seventeen cadaver heads were bisected for a total of 34 sides, which then underwent dissection of the superolateral orbital region to observe the course for the LN and ZTN. Three variations of the course of the LN and ZTN were found. In 20 (60.6%) dissections it was documented that the ZTN entered directly into the lacrimal gland with no communication with the LN. In 12 (36.4%) of the bisected heads, ZTN had both a direct connection into the gland and a communicating branch with the LN. In only one (3.0%) bisected head, ZTN communicated with the LN before entering the gland as it is commonly described in anatomy texts. Our study reveals that the ZTN usually takes a different course than is classically described in most anatomy textbooks. A greater understanding of the typical course these nerves take may help surgeons identify them more easily and avoid damaging them.

Morphology and immunohistochemical characteristics of the pterygopalatine ganglion in the chinchilla (Chinchilla laniger, Molina).

Histological and histochemical investigations revealed that the pterygopalatine ganglion (PPG) in the chinchilla is a structure closely connected with the maxillary nerve. Macro-morphological observations disclosed two different forms of the ganglion: an elongated stripe representing single agglomeration of nerve cells, and a ganglionated plexus comprising smaller aggregations of neurocytes connected with nerve fibres. Immunohistochemistry revealed that nearly 80% of neuronal cell bodies in PPG stained for acetylcholine transferase (CHAT) but only about 50% contained immunoreactivity to vesicular acetylcholine transporter (VACHT). Many neurons (40%) were vasoactive intestinal polypeptide (VIP)-positive. Double-staining demonstrated that approximately 20% of the VIP-immunoreactive neurons were VACHT-negative. Some neurons (10%) in PPG were simultaneously VACHT/nitric oxide synthase (NOS)- or Met-enkephaline (Met-ENK)/CHAT-positive, respectively. A small number of the perikarya stained for somatostatin (SOM) and solitary nerve cell bodies expressed Leu-ENK- and galanin-immunoreactivity. Interestingly about 5-8% of PPG neurons exhibited immunoreactivity to tyrosine hydroxylase (TH). Intraganglionic nerve fibres containing immunoreactivity to VACHT-, VIP- and Met-ENK- were numerous, those stained for calcitonin gene related peptide (CGRP)- and substance P (SP)- were scarce, and single nerve terminals were TH-, GAL-, VIP- and NOS-positive.

Anatomical study of the roots of cranial parasympathetic ganglia: a contribution to medical education.

A major key to increasing the safety of cranial surgery is a thorough understanding of anatomy. The anatomy of the head is of fundamental interest to dental and medical students early in their studies. Clinically, it is mostly relevant to surgeons who are performing interventions and reconstruction in the maxillofacial region, skull base, and the orbit. However, the level of appropriate anatomical knowledge necessary for general and special medical and surgical practice is still under discussion. This study maps the significant areas and structures of the head that are not normally accessible during dissection courses because of time and difficulties involved in the preparation. The detailed photodocumentation enriched by diagrams provides a view of structures until now only partially documented. Three parasympathetic ganglia are located in hardly accessible areas of the head - inside the orbit, infratemporal fossa, and in the pterygopalatine fossa. No detailed photographs have been found in current anatomical textbooks and atlases in relation to the morphology of fibers (roots) connected to the ciliary, otic, and pterygopalatine ganglia. Therefore, this study focused on the detailed display of sensory, sympathetic, and parasympathetic roots of ganglia to provide relevant photodocumentation and an improvement in human anatomy teaching. This study also confirms that cadaver dissection provides an excellent opportunity for the integration of anatomy and clinical medicine into the early clinical training of undergraduate dental and medical students. We believe this article, because of the details mentioned above, will be beneficial not only for the future anatomical undergraduate but also for postgraduate education.

The Sympathetic and Parasympathetic Contributions to the Cardiac Plexus: a Fetal Study / Contribuciones Simpáticas y Parasimpáticas al Plexo Cardíaco: Estudio Fetal

The cardiac plexus is formed by sympathetic nerves originating from the superior, middle, inferior cervical or cervicothoracic ganglia as well as from the first to the fifth thoracic ganglia. Furthermore, the vagus nerve and its counterpart, the recurrent laryngeal nerve supply the cardiac plexus with parasympathetic cardiac nerves. This investigation aimed to review and record the medial contributions of the cervical ganglia, first to fifth thoracic ganglia and medial contributions of the vagus and recurrent laryngeal nerves to the cardiac plexus. The study involved bilateral micro-dissection of forty cadaveric fetal specimens (n=80). The origins of sympathetic contributions to the cardiac plexus were described as either ganglionic, inter-ganglionic or from both the ganglion and the inter-ganglionic sympathetic chain. The number of cervical sympathetic ganglia varied from two to five in this study; the superior cervical ganglion was constant while the middle cervical, vertebral, inferior cervical or cervicothoracic ganglia were variable. The prevalence of cardiac nerves were as follows: superior cervical cardiac nerve (95%); middle cervical cardiac nerve (73%); vertebral cardiac nerve (41%); inferior cervical cardiac nerve (21%) and cervicothoracic cardiac nerve (24%). This investigation records the thoracic caudal limit of the thoracic sympathetic contributions to the cardiac plexus as the T5 ganglion. The findings of this study highlight the importance of understanding the medial sympathetic contributions and their variations to the cardiac plexus as this may assist surgeons during minimal access surgical procedures, sympathectomies, pericardiectomies and in the management of diseases like Raynaud's Phenomenon and angina pectoris.

El plexo cardíaco está formado por los nervios simpáticos procedentes de los ganglios cervicales superior, medio e inferior o cervicotorácico, así como los ganglios torácicos desde el primero al quinto. Por otra parte, el nervio vago y su contraparte, el nervio laríngeo recurrente suministra al plexo cardíaco nervios cardíacos parasimpático. Esta investigación tuvo como objetivo revisar y registrar las contribuciones mediales de los ganglios cervicales, ganglios torácicos del primero al quinto ganglios y contribuciones mediales de los nervios laríngeos recurrentes y vagos en el plexo cardíaco. Se realizó la micro-disección bilateral de cuarenta especímenes cadavéricos fetales (n = 80). Los orígenes de las contribuciones simpáticas hacia el plexo cardíaco se describen de forma independiente como ganglionar o inter-ganglionar, o desde ambos ganglios y la cadena simpática interganglionar. El número de ganglios simpáticos cervicales varió de dos a cinco; el ganglio cervical superior fue constante, mientras que los ganglios medio-cervical, vertebral, cervical inferior o cervicotorácico fueron variables. La prevalencia de los nervios cardíacos fueron: nervio cardíaco cervical superior (95%); nervio cardíaco cervical medio (73%); nervio cardiaco vertebral (41%); nervio cardíaco cervical inferior (21%) y nervio cardíaco cervicotorácico (24% ). La investigación registró el límite torácico caudal de las contribuciones torácicas simpáticos al plexo cardíaco como el ganglio T5. Los resultados de este estudio muestran la importancia de comprender las contribuciones simpáticas mediales y sus variaciones en el plexo cardíaco, ya que podrían ayudar a los cirujanos durante los procedimientos quirúrgicos mínimanente invasivos, simpatectomías, pericardiectomías y en el manejo de enfermedades como el fenómeno de Raynaud y la angina de pecho.

The pterygopalatine ganglion and its role in various pain syndromes: from anatomy to clinical practice.

The postsynaptic fibers of the pterygopalatine or sphenopalatine ganglion (PPG or SPG) supply the lacrimal and nasal glands. The PPG appears to play an important role in various pain syndromes including headaches, trigeminal and sphenopalatine neuralgia, atypical facial pain, muscle pain, vasomotor rhinitis, eye disorders, and herpes infection. Clinical trials have shown that these pain disorders can be managed effectively with sphenopalatine ganglion blockade (SPGB). In addition, regional anesthesia of the distribution area of the SPG sensory fibers for nasal and dental surgery can be provided by SPGB via a transnasal, transoral, or lateral infratemporal approach. To arouse the interest of the modern-day clinicians in the use of the SPGB, the advantages, disadvantages, and modifications of the available methods for blockade are discussed.▪

Human laryngeal ganglia contain both sympathetic and parasympathetic cell types.

The presence of ganglia associated with the laryngeal nerves is well documented. In man, these ganglia have been less well studied than in other species and, in particular, the cell types within these ganglia are less well characterized. Using a panel of antibodies to a variety of markers found in the paraganglion cells of other species, we were able to show the existence of at least two populations of cells within human laryngeal paraganglia. One population contained chromogranin and tyrosine hydroxylase representing a neurosecretory population possibly secreting dopamine. A second population of choline acetyltransferase positive cells would appear to have a putative parasympathetic function. Further work is needed to characterize these cell populations more fully before it will be possible to assign functions to these cell types but our results are consistent with the postulated functions of these ganglia as chemoreceptors, neurosecretory cells, and regulators of laryngeal mucus secretion.

Endoscopic study for the pterygopalatine fossa anatomy: via the middle nasal meatus-sphenopalatine foramen approach.

OBJECTIVE: The purposes of this study were to locate the constant anatomic landmarks, which are very important and helpful for endoscopic surgery and not well described for the pterygopalatine fossa (PPF) surgery via the middle nasal meatus-sphenopalatine foramen approach to establish a safe surgical mode. METHODS: Eight cases of adult skull specimens were selected for the simulated surgery. The Messerklinger surgical approach was used under the endoscope. The uncinate process was removed successively, and the anterior ethmoid sinus and posterior ethmoid sinus were opened. The opening of the maxillary sinus was identified and was expanded forward and backward. The ethmoidal crest was found and was used as an anatomic landmark to find the sphenopalatine foramen. The sphenopalatine artery was protected and was used as a guide to enter the PPF region. The sphenopalatine artery was followed conversely to anatomize the blood vessels and nerves in the PPF. RESULTS: It was found that our surgical procedure provides a clear view of the constant anatomic landmark including ethmoidal crest and sphenopalatine foramen. By retrograde dissection, following the sphenopalatine artery, which runs out of the sphenopalatine foramen behind the ethmoidal crest, the internal maxillary artery (IMA) and the branches of the IMA in the PPF were exposed. Posterior to the sphenopalatine artery, the typical Y-shaped structure with the pterygopalatine ganglion as the center was visible when the IMA and its branches were moved downward and outward. The Y structure, which is consisted of the pterygopalatine ganglion, branches of the internal maxillary nerve, vidian nerve, and descending palatine nerve, served as the other anatomic landmark. By following the Y structure, it was easy to locate the pterygoid canal, foramen rotundum, and the infraorbital nerve, and the integrity of the nerve structure could be protected. CONCLUSION: Endoscopic PPF surgery via the middle nasal meatus-sphenopalatine foramen approach is safe, and the ethmoidal crest, sphenopalatine foramen, and Y structure with the pterygopalatine ganglion in the center are important anatomic landmarks that can be referred to during the surgery.

Anatomic variation of cranial parasympathetic ganglia

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

A computed tomography scan and anatomical cadaveric study of the pterygopalatine ganglion for use in Gamma Knife treatment of cluster headache.

OBJECT: Gamma Knife surgery has recently been used to treat patients with cluster headaches. Both the trigeminal nerve root and the pterygopalatine ganglion (PPG) have been targeted. However, there are no clear-cut anatomical landmarks on computed tomography (CT) scans or magnetic resonance images that accurately identify the PPG. Therefore, the authors performed microsurgical dissections on latex-injected cadaver heads to expose the PPG and correlated the findings with thin-slice axial CT scans obtained in the same heads to determine how best to target the PPG. METHODS: Three cadaver heads (five sides) previously injected with colored latex were dissected using skull base approaches and microsurgical techniques to identify the PPG and surrounding structures. Measurements were then made to different osseous anatomical landmarks such as the foramen rotundum, vidian canal, and so on. The PPG was marked with a radiopaque marker and thin-slice CT scans were obtained in the cadaver heads to develop some correlates that could be used to identify where the PPG is located on CT scans. RESULTS: The PPG was clearly identified in all specimens and had a mean diameter of 3.58 +/- 0.6 mm. The PPG was always located in the same plane (lateral and vertical) as the vidian canal and was located on average 2.7 +/- 0.3 mm from the end of the canal. The vidian canal was clearly identified on coronal CT scans and had a diameter of 3.05 mm. CONCLUSIONS: There was a clear and constant relationship between the PPG and vidian canal. The vidian canal is easily identified on coronal CT scans and can be used as a landmark to target the PPG with the Gamma Knife.

The pterygopalatine fossa: an anatomic report.

The pterygopalatine fossa (PPF) is a small anatomic region of particular interest in cranial base surgery. Infectious diseases and malignancy may spread through the PPF to contiguous areas as a result of the low resistance offered by the numerous foramina and fissures that surrounds the fossa. We present an anatomic report on the PPF. Twelve sides of six fixed cadaveric heads were dissected through a LeFort I maxillary osteotomy with transantral exposure of the neurovascular content of the PPF. Arterial vascular patterns of the maxillary artery were observed. The pterygopalatine fossa is a deeply located small anatomic region with a rich neurovascular content. The third portion of the maxillary artery in the PPF may demonstrate a variable vascular morphology. A correct understanding and knowledge of the anatomic structures lodged into the PPF, as well as their relationships and functions, remain crucial to minimizing postsurgical morbidity and intraoperative complications.

Long-lasting reductions of ethanol drinking, enhanced ethanol-induced sedation, and decreased c-fos expression in the Edinger-Westphal nucleus in Wistar rats exposed to the organophosphate chlorpyrifos.

Intermittent or continuous exposure to a wide variety of chemically unrelated environmental pollutants might result in the development of multiple chemical intolerance and increased sensitivity to drugs of abuse. Interestingly, clinical evidence suggests that exposure to organophosphates might be linked to increased ethanol sensitivity and reduced voluntary consumption of ethanol-containing beverages in humans. The growing body of clinical and experimental evidence emerging in this new scientific field that bridges environmental health sciences, toxicology, and drug research calls for well-controlled studies aimed to analyze the nature of the neurobiological interactions of drugs and pollutants. Present study specifically evaluated neurobiological and behavioral responses to ethanol in Wistar rats that were previously exposed to the pesticide organophosphate chlorpyrifos (CPF). In agreement with clinical data, animals pretreated with a single injection of CPF showed long-lasting ethanol avoidance that was not secondary to altered gustatory processing or enhancement of the aversive properties of ethanol. Furthermore, CPF pretreatment increased ethanol-induced sedation without altering blood ethanol levels. An immunocytochemical assay revealed reduced c-fos expression in the Edinger-Westphal nucleus following CPF treatment, a critical brain area that has been implicated in ethanol intake and sedation. We hypothesize that CPF might modulate cellular mechanisms (decreased intracellular cAMP signaling, alpha-7-nicotinic receptors, and/or cerebral acetylcholinesterase inhibition) in neuronal pathways critically involved in neurobiological responses to ethanol.

The microsurgical anatomy of the ciliary ganglion and its clinical importance in orbital traumas: an anatomic study.

The ciliary ganglion can easily be injured during surgery for the repair of orbital fractures and laterally situated intraorbital mass lesions. The aim of this study is to elucidate the microsurgical anatomy of the ciliary ganglion and to emphasize its clinical importance in orbital traumas and surgeries. The orbits of 10 adult cadavers were fixed with 10 % formalin and dissected under the microscope with special attention to the presence and location of the ciliary ganglion. The motor (parasympathetic), sympathetic, and sensory roots, and the short ciliary nerves were exposed. Its relationship with other intraorbital neural and vascular structures were investigated. Some anatomic landmarks were determined and the distances between these landmarks were measured. The ciliary ganglion is an intraorbital neural structure approximately 3 mm in size, situated near the orbital apex, posterolateral to the globe in loose areolar tissue between the optic nerve and lateral rectus muscle. The mean distance between the ganglion and the optic nerve was 2.9 mm (range: 2.70 - 3.10 mm) and the mean distance between the lateral rectus muscle and the ganglion was 10.4 mm (range: 9.20 - 11.20 mm). Six to 10 short ciliary nerves arise from the ganglion and run forward in a curving manner with the ciliary arteries above and below the optic nerve. The ciliary ganglion should be taken into the account especially during lateral approaches to the orbit and the patients should be warned before the surgery about possible mydriatic or tonic pupils as a complication.

Histochemical Features of the Extracellular Matrix in Rattus rattus norvegicus Otic Ganglion / Características Histoquímicas de la Matriz Extracelular en el Ganglio Ótico de Rattus rattus norvegicus

The otic ganglion is a cranial component of the parasympathetic division of the autonomic nervous system (ANS). Similar to other parasympathetic ganglia, otic ganglion presents multipolar neurons that are completely surrounded by satellite cells and intercellular substance as well, which allow us to use this ganglion as a good experimental model for studying the relationship neuron / extracellular matrix. We have studied rat otic ganglion in 10 animals through light microscopy. After routine histological methods, 5 µm sections were obtained and coloured by Gomori`s trichrome, periodic acid-Schiff (PAS), Alcian Blue pH 2.5 and pH1.0, acetylation + PAS, acetylation + deacetylation + PAS, acid hydrolysis + PAS, phenylhydrazine + PAS and thiosemicarbazide + PAS. The presence of neutral glycoproteins was demonstrated by PAS reactivity. PAS inhibition following Alcian Blue staining in pH 2.5 and 1.0 showed the presence of a small quantity of acid glycoprotein. The extracellular matrix analysis showed the presence of neutral and acid glycoconjugates. These findings suggests a mutual interaction and a complex role in ganglionic physiology.

El ganglio ótico es un componente craneal de la división parasimpática del sistema nervioso autónomo (SNA). Similar al otro ganglio parasimpático, el ganglio ótico presenta neuronas multipolares que están rodeadas totalmente por las células satélites y la sustancia intercelular, lo cual permite la utilización de este ganglio como un buen modelo experimental para estudiar las relaciones matriz extracelular/neurona. Examinamos, con microscopio de luz, el ganglio ótico 10 ratones. Con los métodos histológicos rutinarios fueron obtenidas 5 secciones y coloreadas con tricrómico de Gomori, PAS, Azul de Alcián pH 2.5 y pH1.0, acetilación + PAS, acetilación + desacetilación + PAS, hidrólisis de ácido + PAS, fenilhidrazina + PAS y tiosemicarbacida + PAS. La presencia de glicoproteínas neutras fue demostrada por la reactividad de PAS. La inhibición de PAS y la posterior tinción con Azul de Alcian en pH 2.5 y 1.0, demostró la presencia de una cantidad pequeña de glicoproteínas ácidas. El análisis extracelular de la matriz demostró la presencia de glicoconjugados neutros y ácidos. Estos resultados sugieren una interacción mutua y un papel complejo en la fisiología ganglionar.

[Human and animal ciliary ganglion--history and modern conceptions]. / Resnichnyi uzel cheloveka i zhivotnykh--istoriia izucheniia i sovremennye kontseptsii.

This paper reviews one of the complicated problems of the anatomy of the autonomic nervous system--the structure of human ciliary ganglion (CG). The literature data as well as the results obtained by the department and personally by the authors, are analyzed in three aspects: (a) human CG external structure and topography; (b) CG anatomy in animals and (c) characteristic of neurocytes of human and animal CG. The evidence indicating the absence of sympathetic root in both humans and animals, is presented. The size, shape and topography of CG are interrelated by the features of morphogenesis, thus reflecting it: these parameters are associated with a different localization of neuroblasts--precursor cells for CG neurons in brachicephals and dolichocephals. Authors conclude, that the data obtained in animal experiments cannot be extrapolated to humans, not only due to their contradictory nature, but also because of the definite presence of CG sensory root in man.

Localization of preganglionic neurons that innervate choroidal neurons of pterygopalatine ganglion.

PURPOSE: The pterygopalatine ganglion (PPG) receives preganglionic input from the superior salivatory nucleus (SSN) of the facial motor complex and is the main source of parasympathetic input to the choroid in mammals. The present study was undertaken to determine in rats the location and neurotransmitters of SSN neurons innervating those PPG neurons that target the choroid and to determine the location and neurotransmitters of the PPG choroidal neurons themselves. METHODS: Retrograde labeling from rat choroid using a fluorescent tracer, in combination with immunofluorescence labeling for nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP), and choline acetyltransferase (ChAT), was used to characterize the location and neurotransmitters of choroidal PPG neurons. To identify SSN neurons that innervate the choroidal PPG neurons, the Bartha strain of the retrograde transneuronal tracer pseudorabies virus (PRV-Ba) was injected into rat choroid, and immunolabeling for NOS or ChAT was used to characterize their neurochemistry. RESULTS: Fluorescent retrograde labeling showed that PPG neurons projecting to the choroid contained NOS, VIP, and ChAT and were widely distributed in PPG and its preganglionic root, the greater petrosal nerve. SSN neurons were ChAT(+), and a subset of them was found to contain NOS. PRV-Ba transneuronal retrograde labeling revealed that choroidal preganglionic neurons were localized to the rostral medioventral part of the ipsilateral SSN. The choroidal SSN neurons were ChAT(+) and appeared largely to correspond to the NOS(+) neurons of the SSN. CONCLUSIONS: These results show that preganglionic neurons in rats that are presumed to regulate choroidal blood flow through the PPG reside within the rostral medioventral SSN, and that NOS is a marker for these SSN neurons.

Relation of Fos-IR expression in the pelvic ganglion to sexual behavior in laboratory rats.

The pelvic ganglion (PG) provides both sympathetic and parasympathetic innervation to the genitalia and other pelvic structures. To determine whether neuronal activity; of the PG, as detected by Fos-like immunoreactivity (Fos-IR), is related to sexual stimulation, male and female rats were tested under a variety of conditions. In males, Fos-IR expression in the PG was positively correlated with the amount of both genital and noncontact stimulation. In females, only ejaculation preceded by multiple intromissions induced a significant increase in Fos-IR; multiple intromissions or ejaculation preceded by only 0-1 intromission did not affect Fos-IR. Additional experiments comparing Fos-IR expression, in which some females were allowed to pace their sexual contact and others were not, revealed that ejaculation duration was the key factor in the induction of Fos-IR in female rats. Because the conditions under which Fos-IR expression occurred in females are identical to those required for sperm transport, we suggest that, in the female, sperm transport is regulated in part by autonomic outflow from the PG after copulation. These relations between sexual behavior and measures of PG activity are consistent with the idea that the sexually dimorphic organization of the peripheral nervous system plays a major role in mediating the gender-specific outcome of copulation: ejaculation in the male and sperm transport in the female.

A parasympathetic ganglion innervating the harderian gland and lacrimal gland of the musk shrew (Suncus murinus): fluorescent tracing and immunohistochemical studies.

A small ganglion, named the peri-trigeminal ganglion (PTG), was found in the ventromedial border of the rostral half of the trigeminal ganglion (TG) in the musk shrew (Suncus murinus). In frontal sections, the PTG was semicircular or elliptical in shape. Most of the neurons constituting this ganglion were round in shape and much smaller than those of the TG. The retrograde fluorescent tracer fluoro-gold was injected into various regions of the face in order to investigate innervation by the PTG neurons. When the tracer was injected subcutaneously around the external acoustic meatus and around the circumference of the orbit, a number of labeled neurons were seen not only in the TG but also in the PTG. After applying the tracer to the lacrimal gland (LG) and the harderian gland (HG), numerous labeled neurons were detected only in the PTG. A few labeled neurons were found in the PTG after injection into the palatoglossal arch. Immunohistochemically, most of the neurons constituting the PTG were positive for vasoactive intestinal polypeptide (VIP) antiserum. And a moderate number of somatostatin (SOM)-immunoreactive neurons and a small number of leucine-enkephalin (L-ENK)-immunoreactive neurons were detected. Numerous substance P-immunoreactive nerve fibers and varicosities were found in the PTG, and fewer L-ENK-, SOM- and VIP-immunoreactive fibers were observed. The present results suggest that the PTG is an autonomic ganglion that resembles in part the pterygopalatine ganglion in other species, and mainly innervates the HG and LG.