Macro anatomical investigations of the cranial cervical ganglion in domestic pig (Sus scrofa domesticus)

In this study, the left and right cranial cervical ganglia (ganglion cervicale craniale) of eight young (four male, four female) domestic pigs weighing around 70-80 kg were inspected macro anatomically. The cranial cervical ganglion (CCG) was found cranio-ventrally of the distal ganglion of the vagus nerve, medial of the jugular process extremity, ventral of the atlas, dorsal of the epiglottis base and medial of the common root (CR) established by the internal carotid and occipital arteries. The internal carotid nerve and jugular nerve ramified from the cranial part of CCG. The jugular nerve gave branches that merged with the vagus and glossopharyngeal nerves. Other nerve branches originating from the cranial part of the ganglion reached to the external carotid artery and CR. The internal carotid nerve varied among cadavers in number of branches (two to four). These branches did not travel along the side of the internal carotid artery. The central part of CCG gave thin nerve branches that reached to various anatomical structures including the first and second cervical nerves, wall of the pharynx, accessory nerve, hypoglossal nerve, vagus nerve, external carotid artery and CR. The caudal part of CCG gave nerve branches that merged with the vagus, cranial laryngeal nerves, and common carotid artery. The external carotid nerves, which were two or three in number, also originated from the caudal part of CCG. In conclusion, the nerves ramifying from CCG of the pig varied in number among cadavers. Compared with literature raised in other species, there are also differences in number of nerve branches and course pattern of these nerves.     

Dorsal Nerve Root Origins of the Cutaneous Nerves of the Feline Pelvic Limb

The dorsal root origins of cutaneous nerves supplying the feline pelvic limb were determined electrophysiologically in 11 cats. Cutaneous nerves were surgically exposed and the presence or absence of an evoked potential in response to stimulation of individual dorsal roots was noted. The dorsal cutaneous branches of L3-L5 and S3, and the lateral cutaneous branch of L3 each arose solely from their parent spinal nerves. The L7, S1, and S2 dorsal cutaneous branches had multiple dorsal root origins. The lateral cutaneous femoral nerve originated from L3-L6 dorsal roots in 4 patterns of origin, and the saphenous nerve originated from L4-L6 dorsal roots in 2 patterns of origin. The lateral and caudal cutaneous sural nerves originated from L6-S1 roots in 2 and 3 patterns, respectively. The lateral and medial plantar nerves arose from L6-S2 roots in 4 and 2 patterns, respectively. The superficial and deep peroneal nerves originated from L6-S1 roots in 2 and 3 patterns, respectively. The caudal cutaneous femoral nerve or its branches arose from L7-S3 in 8 origin patterns. The dorsal nerve of the penis and the superficial perineal nerve arose from L7-S3 and S1-S3 roots, respectively, each in 4 patterns. A subtle correlation between plexus type and dorsal root origins of the cutaneous nerves was noted.     

The spinal nerves that constitute the lumbosacral plexus and their distribution in the chinchilla

In this study, the spinal nerves that constitute the lumbosacral plexus (plexus lumbosacrales) (LSP) and its distribution in Chinchilla lanigera were investigated. Ten chinchillas (6 males and 4 females) were used in this research. The spinal nerves that constitute the LSP were dissected and the distribution of pelvic limb nerves originating from the plexus was examined. The iliohypogastric nerve arose from L1 and L2, giving rise to the cranial and caudal nerves, and the ilioinguinal nerve arose from L3. The other branch of L3 gave rise to the genitofemoral nerve and 1 branch from L4 gave rise to the lateral cutaneous femoral nerve. The trunk formed by the union of L4-5 divided into medial (femoral nerve) and lateral branches (obturator nerve). It was found that the LSP was formed by all the ventral branches of L4 at L6 and S1 at S3. At the caudal part of the plexus, a thick branch, the ischiadic plexus, was formed by contributions from L5-6 and S1. This root gave rise to the nerve branches which were disseminated to the posterior limb (cranial and caudal gluteal nerves, caudal cutaneous femoral nerve and ischiadic nerve). The ischiadic nerve divided into the caudal cutaneous surae, lateral cutaneous surae, common fibular and tibial nerve. The pudendal nerve arose from S1-2 and the other branch of S2 and S3 formed the rectal caudal nerve. The results showed that the origins and distribution of spinal nerves that constitute the LSP of chinchillas were similar to those of a few rodents and other mammals.     

Myelinated axons in peripheral nerves of adult beagle dogs: morphometric and electrophysiological measurements

The myelinated fibre composition and conduction velocities were measured for the ulnar, saphenous and caudal cutaneous sural nerves of 10 healthy beagle dogs. A systematic random sampling technique was used to estimate the fibre diameter frequency distributions and densities. Conduction velocities were measured from evoked compound nerve action potentials. All nerves showed bimodal diameter frequency distributions with modes being approximately the same for each nerve (2 to 4 microns and 8 to 10 microns or 10 to 12 microns). The variation in the average densities and in the shapes of histograms of the different nerves was slight; however, there was a wide variation for the same nerve in different individuals. The conduction velocities for the fastest conducting axons in the nerves ranged from 63 to 79 m s-1. These normal quantitative processes affecting peripheral nerves in the dog.     

Neurophysiologic maps of the cutaneous innervation of the external genitalia of the ewe

The area of skin supplied by the afferent fibers in a peripheral nerve is called the cutaneous area (CA) of that nerve. The CA responsive to movement of wool or hair in the genital regions were mapped in 17 ewes, with the identifications of the peripheral nerves and of the spinal nerves contributing to the pudendal plexus being checked at necropsy. Differences were found in the origins and extent of CA of the cutaneous branches from the sacral plexus. The CA of the caudal rectal nerves and of a nerve that passed caudally between the caudal vertebrae and the ventral sacrococcygeus muscle lay lateral to the anus and in the adjacent skin of the tail. The CA of the proximal cutaneous branch and of the distal cutaneous branch from the pudendal nerve (or plexus) overlapped craniocaudally (by approx one-half) the CA of the distal cutaneous branch extending ventrally and ending just caudal to the ipsilateral mammary gland. The deep perineal nerve innervated the skin immediately lateral to the anus and vulva. The dorsal nerve of the clitoris innervated hairs on the ipsilateral half of the vulva. Other fibers in the pudendal nerve were presumed to pass into the mammary branch of the nerve. They innervated the skin ventral to the vulva, the ipsilateral mammary gland, and (in some ewes) areas of the skin cranial to the mammary gland. The CA of the genitofemoral nerve included the ipsilateral teat and the inguinal fossa.(ABSTRACT TRUNCATED AT 250 WORDS)     

A Macroscopic Investigation of the Nerves to the Eye and Ocular Annexes in the Van Cat

The orbital nerves were examined grossly in eight adult Van cats from either sex. The optic nerve, in a sigmoid curl, reached the eyeball after coursing between the retractor bulbi and medial rectus muscles. The oculomotor nerve gave off dorsal and ventral branches between the retractor bulbi and lateral rectus muscles. The ciliary ganglion was located on the lateral subbranch of the ventral branch of this nerve in all materials. There were short ciliary nerves originated from the ciliary ganglion in all the materials observed. The lacrimal nerve was a branch of the maxillary nerve.     

Development and verification of saphenous, tibial and common peroneal nerve block techniques for analgesia below the thigh in the nonchondrodystrophoid dog

OBJECTIVE: To document simple and reliable local, infiltrating nerve blocks for the saphenous, tibial and common peroneal nerves in the dog. STUDY DESIGN: Laboratory technique development; in vivo blind, controlled, prospective study. ANIMALS: Twenty canine cadavers and 18 clinically normal, client-owned dogs. METHODS: A peripheral nerve blockade technique of the tibial, common peroneal, and saphenous nerves was perfected through anatomic dissection. Injections were planned in the caudal thigh for the tibial and common peroneal nerves, and in the medial thigh for the saphenous nerve. Cadaver limbs were injected with methylene blue dye and subsequently dissected to confirm successful dye placement. Clinically normal dogs undergoing general anesthesia for unrelated, elective procedures were randomly assigned to treatment (bupivacaine; n = 8) or control (saline; n = 8) nerve blocks of the nerves under study. Upon recovery from general anesthesia, skin sensation in selected dermatomes was evaluated for 24 hours. RESULTS: Cadaver tibial, common peroneal, and saphenous perineural infiltrations were successful in nonchondrodystrophoid dogs (100, 100, and 97%, respectively.) Intraneural injection was rare (1%; 1/105; tibial nerve) in cadaver dogs. In the treatment group of normal dogs, duration of loss of cutaneous sensation in some dermatomes (saphenous, superficial and deep peroneal nerve) was significantly different than control dogs; the range of desensitization occurred for 1-20 hours. No clinical morbidity was detected. CONCLUSIONS: This technique for local blockade of the tibial, common peroneal, and saphenous nerves just proximal to the stifle is easy to perform, requires minimal supplies and results in significant desensitization of the associated dermatomes in clinically normal, nonchondrodystrophoid dogs. CLINICAL RELEVANCE: This technique may be an effective tool for post-operative analgesia to the femoro-tibial joint and distal pelvic limb. Other applications, using sustained-release drugs or methods, may include anesthesia/analgesia in high-risk patients or as a treatment for chronic pelvic limb pain or self-mutilation.     

Origin and distribution of the brachial plexus of the Van cats

Knowing the structure and variations of the plexus brachialis is important in neck and shoulder surgery. The knowledge of the brachial plexus reduces the injury rate of the nerves in surgical interventions to the axillary region. The major nerve trunks of the thoracic limb were the suprascapular, subscapular, axillary, radial, musculocutaneous, median and ulnar nerves. In Van cats, the brachial plexus was formed by the ventral branches of the spinal nerves, C6-C7-C8 and T1. The 7th cervical nerve was quite thick compared to the others. The subscapular nerve was the thinnest (on the right side, the average length was 6.55 ± 0.60 mm and on the left side was 6.50 ± 0.60 mm), and the radial nerve was the thickest (the average length on the right side was 28.48 ± 0.44 mm and on the left side was 29.11 ± 0.55 mm). The suprascapular nerve was formed by the ventral branch of the 6th cervical nerve. The subscapular nerves were formed by a branch originating from the 6th cervical nerve and the two medial and caudal branches originating from the 7th cervical nerve. No communicating branch between the ulnar nerve and the median nerve was observed in the palmar region. The axillary nerve was formed by the ventral branches of the 7th nerve, the musculocutaneous nerve was formed by ventral branches of the 6th and 7th cervical nerves, and the ulnar nerve was formed by ventral branches of the 8th cervical and the 1st thoracic nerves. The radial nerve was the thickest branch in the brachial plexus. In Van cats, the origin and distribution of nerves were similar to those reported in the literature for other species of cats, with the exception of the suprascapular, subscapular and axillary nerves.     

Innervation of the wing membrane in the bent-winged bat Miniopterus fuliginosus

The nerves that innervate the fingertips and wing membrane from the upper arm of the bent-winged bat Miniopterus fuliginosus were examined under a stereomicroscope. The radial, median, ulnar and musculocutaneous nerves were formed by the brachial plexus, which ran to the wing membrane. The two suspected axillary nerves ran to the wing membrane. The radial nerve ran to the end of the first digit, while the median nerve ran along the forearm and subsequently branched-off to run along the second to fifth digits up to the end of the phalanges. The ulnar nerve ran to the plagiopatagium on the extensor side of the elbow joint. Finally, the musculocutaneous nerve passed through the ventral side of the humerus and branched out at the elbow joint to run radially to the propatagium area. In this study, the visible nerves that were distributed from the upper arm to the fingertips of Miniopterus fuliginosus were formed by C6–T1.     

Effects of cryotherapy on the palmar and plantar digital nerves in the horse

The duration of anesthetic effect and the histopathologic changes resulting from a controlled freeze of the palmar and plantar digital nerves in the horse were evaluated. Two techniques were compared: (i) nerves were frozen by direct application of the cryoprobe after surgical exposure and (ii) nerves were frozen by percutaneous application of the cryoprobe to the overlying skin. Return of skin sensation and ability to detect a stimulus were used to determine return of nerve function. The duration of anesthetic effect was significantly (P less than 0.005) longer for nerves frozen after surgical exposure than for those frozen by the percutaneous technique (mean 156 days vs 47.5 days). At the termination of the study, horses were euthanatized and all nerves were examined histologically. Neuromas-in-continuity were observed in 10 of 28 frozen nerves. Classification was based on the involvement of the supporting fibrous connective tissues of the nerve, endoneurium, perineurium, and epineurium. The direct technique of freezing the nerve after surgical exposure was repeatable and could be used to provide temporary neurectomy in the horse. The percutaneous technique caused a temporary loss of pain perception, but could not be relied on to interrupt nerve function for longer than a few weeks.     

Function of the ramus communicans of the medial and lateral palmar nerves of the horse

Reasons for performing study: The role of the communicating branch between the medial and lateral palmar nerves of horses (i.e. the ramus communicans) in conveying sensory impulses proximally should be determined to avoid errors in interpreting diagnostic anaesthesia of the palmar nerves. Hypothesis: Sensory nerve fibres in the ramus communicans of horses pass proximally from the lateral palmar nerve to merge with the medial palmar nerve, but not vice versa. Objective: To determine the direction of sensory impulses through the ramus communicans between lateral and medial palmar nerves. Methods: Pain in a thoracic foot was created with set‐screw pressure applied to either the medial or lateral aspect of the sole of each forelimb of 6 horses. The palmar nerve on the side of the sole in which pain was created was anaesthetised proximal to the ramus communicans with local anaesthetic. Lameness was evaluated objectively by using a wireless, inertial, sensor‐based, motion analysis system (Lameness Locator). Lameness was also evaluated subjectively by using a graded scoring system. Local anaesthetic was then administered adjacent to the ramus communicans to determine the effect of anaesthesia of the ramus communicans on residual lameness. Results: When pain originated from the medial or the lateral aspect of the sole, anaesthesia of the ipsilateral palmar nerve proximal to the ramus communicans did not entirely resolve lameness. Anaesthesia of the ramus communicans further attenuated or resolved lameness. Conclusions: Sensory fibres pass in both directions in the ramus communicans to connect the medial and lateral palmar nerves. Potential relevance: When administering a low palmar nerve block, both palmar nerves should be anaesthetised distal to the ramus communicans to avoid leaving nondesensitised sensory nerve fibres passing through this neural connection. Alternatively, local anaesthetic could also be deposited adjacent to the ramus communicans when anaesthetising the palmar nerves.     

Different patterns of vasoactive intestinal polypeptide (VIP)-immunoreactive and acetylcholinesterase (AChE)-positive innervation in the internal carotid artery and cerebral arterial tree of the quail

The innervation pattern of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) nerves in the quail internal carotid artery (ICA) and cerebral arterial tree was investigated and compared with that of acetylcholinesterase-positive (AChE-P) nerves. The supply of VIP-IR nerves to the two arterial systems was distinctly richer than that of AChE-P nerves. It was focused mainly on the walls from the distal ICA to the caudal half of the anterior ramus (AR) through the cerebral carotid artery (CCA). Indeed, double staining clearly showed that numerous VIP+/AChE-axons were distributed over these arterial regions where VIP+/AChE+ or AChE+/VIP- axons were sporadic or often lacking. The finding that nerve bundles accompanying the ICA within the carotid canal contained abundant VIP+/AChE- nerve cells suggests that cerebrovascular VIP-IR nerves in the quail have their major source at these neurons and enter the cranial cavity through the CCA. Another significant finding was that a small number of nerve cells, which were mostly stained for AChE alone and occasionally for VIP alone or both, occurred in the major arteries located more rostral than the middle AR. Thus, the quail cerebral arterial tree, at least the rostral segment of the anterior circulation, is multiply innervated by these three distinct categories of the extracranial and intracranial VIP-IR and AChE-P neurons.     

Spinal Root Origin of the Radial Nerve and Nerves Innervating Shoulder Muscles of the Dog

The ventral spinal root origin of the radial nerve, its muscle branches, and brachial plexus nerves which supply shoulder and thoracic musculature was determined in the dog. Electrophysiological signal averaging techniques measured evoked potential from specific ventral spinal roots to individual muscle nerves. The entire radial nerve received input from the sixth cervical (C6) through the second thoracic (T2) spinal roots. The most significant (p less than .05) input to triceps brachii came from C8 while the deep ramus of the radial nerve received its largest input from C7. The brachiocephalicus, suprascapular, and subscapular nerves all received their most significant (p less than .05) innervation from C6. Approximately 90% of the evoked potential to the axillary nerve originated from C7. The thoracodorsal nerve received most of its innervation from ventral roots C7 and C8. The lateral thoracic nerve which innervates the cutaneous trunci muscle was supplied by ventral roots C8-T2. Examination of innervation patterns suggests that only modest variation of spinal root input to specific nerves occurred between individual dogs.     

B-cell lymphoma in the peripheral nerves of a cat

A B-cell, Burkitt-type lymphoma, diffusely affecting the peripheral nerves and intramuscular nerve branches was diagnosed in a 4-year-old domestic shorthair cat with a chronic progressive history of flaccid tetraparesis and generalized muscle atrophy. There was no evidence of cranial nerve, central nervous system, radicular, bone marrow, splenic, or lymph node involvement. The cat tested negative for feline retroviruses and a wide variety of herpes viruses, including Epstein-Barr virus. The clinical manifestation of this case was similar to the chronic polyneuropathic variant of human diffuse neurolymphomatosis; a condition most commonly caused by an axonopathy resulting from infiltration of peripheral nerves with non-Hodgkin's lymphoma.     

Anatomical study of the ventral rami of thoracic spinal nerves in Sapajus apella (Primates: Cebidae)

This study aimed to describe the gross anatomy of the ventral rami of the thoracic spinal nerves in capuchin monkey (Sapajus apella) and compare with humans and other primate species. Eight specimens, prepared in 10% formalin solution and dissected following routine standard techniques, were used. The animals presented 13–14 pairs of thoracic spinal nerves emerging from the intervertebral foramen and divided into dorsal and ventral rami. The ventral rami of the first 12 or 13 pairs represented intercostal nerves and the latter referred to the subcostal nerve. The intercostal and subcostal nerves gave off muscular and cutaneous branches (lateral and ventral), which promote innervation of muscles and skin associated with the chest and abdominal wall. Atypical anatomy was verified for the 1st, 2nd and 7th to 13th intercostal nerves as well as for the subcostal nerve. The morphological characteristics were similar to those observed in humans and some non‐human primates, especially in the absence of collateral branches.     

Nerve distribution in the metacarpus and front digit of the horse.

The nerve distribution to the digit of the horse was studied with the compound microscope in serial transverse sections of fetal limbs and plotted on life-size outlines of the horse's foot. It was learned that there is much variation in the topography of the branches of the principal nerves. There is no mirror-image nerve distribution on the 2 sides of the foot. The dorsal branch of the ulnar nerve does not extend below the fetlock. The communication between the palmar metacarpal nerves and branches of the dorsal branch of the digital nerves is only a crossing of nerves without exchange of fibers. The palmar metacarpal nerves usually do not innervate structures distal to the pastern joint. The innervation of the deep structures of the equine foot was tabulated.     

Gross morphological features of plexus brachialis in the chinchilla (Chinchilla lanigera)

This study documents the detailed features of the morphological structure and the innervation areas of the plexus brachialis in the chinchilla (Chinchilla lanigera). The animals (5 female and 5 male) were euthanased with ketamine hydrocloride and xylazine hydrocloride combination, 60 mg/kg and 6 mg/kg, respectively. Skin, muscles and nerves were dissected under a stereo-microscope. The brachial plexus of the chinchilla is formed by rami ventrales of C5-C8, T1 and T2, and possesses a single truncus. The subscapular nerve is formed by the rami of the spinal nerves originating from C6 (one thin ramus) and C7 (one thick and 2 thin rami). These nerves innervate the subscapular and teres minor muscles. The long thoracic nerve, before joining with the brachial plexus, obtains branches from C6 and C7 in 5 cadavers (3 male, 2 female), from C7 in 4 cadavers (2 male, 2 female) and from C6-C8 in only 1 female cadaver. These nerves disperse in variable combinations to form the extrinsic and intrinstic named, nerves of the thoracic limb. An undefined nerve branch originates from the rami ventrales of C7, C8 and T1 spinal nerves enter the coracobrachial muscle.     

Anatomy of the Thoracic Splanchnic Nerves in Pigs

The anatomical features of the autonomous nerves, including the greater, lesser and least splanchnic nerves, were examined in 4 female and 4 male adult pigs (Sus scrofa). The origin and course of these nerves were examined with regard to sex and the side of the body. The greater splanchnic nerve was present in all of the animals included in the study, whereas the lesser splanchnic nerve was present at a rate of 87.5% on the right side and 75% on the left side of the median plane. On the other hand, the least splanchnic nerve was present on the right side at a rate of 62.5% and on the left side at a rate of 37.5%. The greater, lesser and least splanchnic nerves on the right side of the median plane were determined to originate from a more cranial location. Furthermore, these nerves were observed to be longer and larger on the right side in comparison with the left side. Evaluation of the findings revealed no significant difference between both sides of the median plane with regard to the origin, course and dimensions of these nerves. Similarly, no significant difference was detected between sexes.