Anatomy University Michigan Ann brain stem inner ear cholinesterase - PDF document

Anatomy, University Michigan, Ann brain stem, inner ear cholinesterase technique inner ear are part visceral efferent system the facial, immersed for three Sections were a total on slides with permount. carried out. sections were The brains, treated iden- to determine whether differences were noted between these animals and generally yielded when longer incubation times were used to two pretreatment with brains and procedure outlined diminished quantitatively, actions are never results, obtained was essentially the pH bating medium cedure was mend a considerable diffusion artifact frequently masks the eliminates some olive, or nucleus trape- cholinesterase with pH use

d possessing cytoplasmic dorsolateral border. marginal and the neurons the lateral Prominent dorsal tend from facial nucleus anteriorly with and is fusiform neurons with eccentric nuclei. have long dorsal, medial which was tegmentum; the the lateral, at the lateral grouped multipolar reactivity which merges with ventral nucleus There are present are fusiform neurons the lateral olivary com- them can the latter present material. pathway referred distributed along their centrifugal bundle into three nuclear the facial the facial perior salivatory nucleus. Additionally, a small nucleus located ventrally the lateral cochlear bundle.” Medial to the facial two types be

distinguished both morphologically to be typical preganglionic here. The more cells. They have processes, one superior olivary and the rostomedialward toward the midline nucleus ventrolateral to the genu nerve consists polar and these cells their axons ventralward with the distal nerve, while either collaterals others are efferent bundle. superior salivatory nucleus is a small cluster terase-positive cells the medulla, efferent bundle This nucleus is located the lat- fasciculus solitarius. The su- perior salivatory the larger inferior slender column These three nuclei are linked together the laterally coursing efferent which their cells to the a decussation most rostr

a1 the facial genu (fig. not all the nuclei contribute fibers to the contra- the available shown with across the been called across the dorsolateral tegmentum fascicles diverge the bun- which ultimately supplies branch, the be considered prominent, fascicle loops dor- the small this fascicle also considered fascicles distribute nervus interme- them leaves the the superior nervus intermedius at the the brain stem. from the through the spinal and tract the trigeminal the medial fascicle may join the centrifugal fibers to inner ear ventralward to nervus intermedius. centrifugal bundles the lateral the medulla mouse: a large a small bundle. large bundle is the visceral eff

erent system the superior whereas the small bundle arises larly from the cells related origin, but The small bundle enters the central and remains somewhat independent course, giving no collaterals either the prim- ary acoustic or to the large efferent in part a small the ventrolateral ganglion (fig. a few efferent bundle from the neurons trace, but appear to vestibular nerve The large efferent bundle lateralward from the superior dorsal border the spinal trigeminal nerve and enters medial aspect bular root. bundle projects collaterals from the the primary The collaterals and end in the somata the neurons. the latter acetylcholinesterase-positive, while the majority b

undle continues the ventral cochlear nucleus, few collaterals to the bundle already described, vestibular ganglion. Some fibers this bundle but the curves around cochlear nerve bundle.” while the other the main trunk these preganglionic fibers begin as for terminate among small clusters the tunica proximally along within the vestibular ganglion. minimally or moderately their axons corresponds to vestibular nerve. to the which occur course. Many these postgan- was detected these postganglionic these postganglionic fascicle which same general midmodiolar regions, spiral bundle where cates; one branch turns other, basalward in the course; these different routes throu

gh the spiral they join intraganglionic spiral ganglion to intraganglionic spiral bundle spiral bundle mouse, which one another eccentric nuclei, and are (around 10 moderately reactive reactive to any extent for terminals and vestibular postganglionic Not all with certainty. to blood the latter are not the crista where they work (fig. cells differ the upper both acetylcholinesterase cholinesterase, whereas the upper either substrate. macular areas, terminals are cochlear postganglionic cochlear postgan- a vascular Other postganglionic fibers them bifurcate and loops or plexus. Still the axons nervosa. The peripherally coursing Orthosympathetic fibers. esterase-positiv

e fibers anterior inferior cochlear nerve (fig. course along the para- sympathetic bundles and through the cochlear nerve. their termination present material as the staining the parasympathetic and the reactive fibers which course cochlear nerve through the spiral ganglion to the intra- ganglionic bundle. ity exists The distal neurons are the first node distally into the organ occurs in the internode and around these processes the foramen not present distal acting distal sensory processes fibers winding case such a fine fiber the foramen rise to the distal neuron (fig. Whether the stem the term- conclusively shown the present here there are the spiral ganglion (fig. ne

urons are the spiral near the intragan- cells sometimes eccentric nucleus which at the membrane, particularly though the axolemma when incubation solutions is high occurs cytoplasmically nor their sheaths stain the neurons this respect the spiral intraganglionic spiral Efferent fibers frequently appear around the somata cholinesterase-positive bipolar this contact efferent fibers and observed only but might the vestibular areas. research must determine whether not such contact relationships the eighth nerve have been described in the the latter part nineteenth century comprehensive review, see and Cortesina, thought such preganglionic salivatory nervus intermedius. th

e centrifugal been considered to superior olivary complex which resulted a bundle which then contralateralward ventral the facial vestibular nerve. Rasmussen was tracing the into the cochlear." Papez located either nucleus, or the nucleus Rasmussen postulated origin were a parasympathetic bundle, basing this and on the Fernandez ('51), and Portmann this bundle reached the inner hair bundle might 1953 that not all cut the thought the to be spiral gan- cells misplaced along ('60), he opossum, dog, and found the bundle remarkably similar respect to size, workers who have in- the bundle are Nomura and the authors efferent innerva- Churchill, Schuknecht described acetylchol

inesterase activity the centrifugal Lundquist ('61) acetylcholinesterase activity culated terminals ending on hair the organ been described Iurato ('62), findings reported mussen's thesis the bundle he parasympathetic, although the origin do to be olivary complex mouse nor to the are spread nucleus laterally. into three one medial genu; one ventrolateral to the ventral the lateral additional nucleus the lateral vestibular nucleus. The neu- rons are cytoplasmically local- ('59) found preganglionic cells. form a bundle which is partly (through the fibers which accompany nerves distally. The rest the facial brain stem. the particular may differ location, this the present,

visceral efferents salivary glands pursue the same system described visceral efferent. arise bilaterally situated medial near the cluded, on situated, in authors and many others (Yagita clustered around the facial were described on the histochemical results and Shute Shute and nucleus (Yagita, been de- the genu into the vestibular central route and vestibular root is, for the nervus intermedius been ignored olivo-cochlear bundle. fibers to the inner ear nervus intermedius. This been suggested the component from the into the vestibular Van Buskirk intermedius and the cat. Literature pertaining to bundle is scarce are not Rasmussen's predication crossed olivo-cochlear

Cortesina, '63, '65b; Shute and According to crossed bundle. these points wide disagree- prevails. Rasmussen's retrograde degeneration studies the medial contribute to the bundle, for occasional atypical cell this nucleus lowing section the decussating fascicle. The direct component to efferent bun- centrifugal bundle, agreement with These nuclei the medial cells morphologically a reticular nucleus the raph6; field, with one other within Attempts to discover bular efferents experimentally difficulty. Gacek without anatomical the lateral vestibular nucleus vestibular nerve. origin to fibers, while vestibular regions. The present results in the the superior agrees essen

- tially with zoid body but the present research indicates these cells lie the lateral with prior tailed descriptions this nucleus '09; Poliak, '2E), (Harrison and the cat The few more medially fusiform neurons the lateral nucleus and may medial preolivary and Warr ('61) found the cat. The medial preolivary cludes this a primary efferent fibers inner ear. and Cortesina probably correspond similarly located their "interposed" the lateral third nucleus which they describe the inner clusion could be reached concerning definition, retic- the central system (Rossi and Zanchetti, that the fibers to the inner superior olivary complex. olivo-cochlear bundle olivary complex was

overlooked. efferent bundle the ventral Comparable relays exist though their distribution terminating around small cells these cells be followed to a termination histochemical technique described this axons. These cells may at the outflow to acoustic stim- The peripheral the intraganglionic close agree- '53) for the the cat, the parent bundle provides vestibular terminate, perhaps completely, upon neurons scattered their courses. Within Ions are embedded within the intraganglionic spiral histochemical reaction pronounced between the inner ear cells differ from one another been reported previously (Gia- cobini, '56; Holmstedt, Learning and et al., Vestibular postgangli

onic fibers termi- predominantly among epithelial cells maculae and ampullary crests. the latter case the innervated These cells to be secretory, based upon their histochemical reaction terase and their nerve supply, Dohlman ('64, bers do not secretory epithelium. their termi- nation, but spiral lamina. Others, which histochemical properties postganglionic autonomic fibers, or networks bipolar neu- wrap around on the the latter the foraminanervosa mentioned observing some vestibular cochlear bipolar gan- cells. The fibers described regions classically considered visceral effer- system. These might suggest morphological basis autonomic modification also pro- morphologi

cal basis for the centrifugal bundle the inner ear auditory nerve ac- tivity (Galambos, '56) and increased '62; Desmedt neurotrophic influence sensory ter- direct or indirect, through regulation supply or fluid balance. Much the inner ear are cut centrally (Engstrom Gacek, '63; Spoendlin, '66) or peripherally Gacek, '63) ulated terminals cells degen- Additionally, some investigators the hair cells largely when the trally (Schuknecht, Smith and Rasmussen, '63). These re- physical continuity vesiculated ter- the organ Corti with cells lying medulla when, they do to prove this, the en- from its its terminals studies have shown unequiv- ocally, however, tact centrifugal or

completely The exact reason upon removal intraganglionic spiral bun- a parasympathetic plexus, bundle. Orthosympathetic fibers with it. finding sup- Lorente de acetylcholinesterase-positive bipolar are unusual neurons and ganglionic cells. They neurons and have no butyrylcholines- the spiral autonomic fibers, their distal resemble autonomic some bipolar the foramina species variation. Nevertheless, and are necessarily efferent. Acetylcholinester- sensory ter- El Rakhawy completely unknown. Animals used this study from the Elizabeth Barto, the author for her with photography. LITERATURE CITED the facialis, 38: 274-291. nique for the inner ear Einfluss des das Innenohr

. E. 1959 Ram& y 1960 Experimental anatomi- Vestibular Systems, edited bv P., L. Gisselsson Charles C Thomas, Springfield, Illinois. Chap. XXII, 297-323. the fas- the labyrinth 1961 Cholinesterase Cholinesterase, Symposium Basel 1960. Bibl. N., N. Alberti 1961 The distribution autonomic ganglia ase, Symposium Basel 1960. Sympathetic enhance- motrices et nerf facial. Private 1956 Acetylcholinesterase activity 192: 1263-1265. Amer. otol. Acta Oto-laryng. spindles to stimula- Cholinesterase, Symposium 1960. Bibl. anat. (Basel), 49: 109-118. 1960 Electron micrographic studies receptor cells Systems, edited Charles C Thomas, Illinois. Chap. Engstrom, H., Fernandez 1961 sion

following The innervation (Guinea Pig). fibers to Auditory activity Acta physiol. Das Ganglion und das Tuberculum acusticum beim Menschen. Gacek, R. 1960 Efferent Vestibular Systems, edited by G. Charles C Springfield, Illinois. Chap. Acetylcholinesterase activity stato-acoustic nerve. 1956 Suppression 1959 Cholinesterase Histochemical Contribution Problems). Pergamon Press, New York. Histochemical demonstra- acetylcholinesterase activity cochlear nuclei 1962 Cholinesterase relation to nerve endings choline method for the application. Acta physiol. scand., Cell Res., rat. Kumamoto to the pig. Acta 55: 11-32. G. B. the rat. Centrum der dem Nervus Der Nucleus salivator

ius chordae quantitative study the small intestine C. C. visceral efferents modified Koelle technique. Nature, nerve. Laryngoscope, 43: 1-38. Zur Endigung des Nervus Histochemical demonstration Arch. Otolaryng., fiber connections. Neurol. Psychiat., experimental investiga- efferent fiber vestibular neuroepithelium. 183: 1743-1744. 178: 1291-1293. koordinierten motorischen Apparaten des Hirn- stammes. Eine cochl6aires. Thesis, Imprimerie-Librai- Saint-Christoly, Bordeaux. cochl6e. Rev. G. L. olivary complex. cochlear bundle. Vestibular Systems, Springfield, Illinois. R. R. fiber com- vestibular nerve cat. Anat. 130: 361-368. Rossi, G., efferent innervation stem reticula

r 95: 199-435. cochlea. Arch. Otolaryng., sympathetic nervous relation to and P. esterasecontaining pathways 205: 242-246. the internal nerve endings Cell Biol., 26: 63-76. pig cochlea. nerve endings the external ische Untersuchungen Cortischen Organ Ruedi, Basel ferent innervation Brain stem Van Buskirk, seventh nerve 82: 303-335. Van Gehuchten, P. Recherches exp6ri- Neurofibrillar development the central nervous system In: Neural Systems, edited Springfield, Illinois. Speichelzentrum. Anat. Einige Experimente des Ursprungsgebietes Nerven. Folia inferior cerebellar at the crista ampullaris neuron distal Crista ampullaris Distal portion Efferent visceral fascicle Faci

al nucleus Foramen nervosum spiral bundle visceral efferent Main visceral efferent Macula sacculi Postganglionic cells Reticular cells Superior salivatory Spiral ganglion Spiral limbus Superior olivary Vestibular ganglion laterally coursing efferent bundle (VE). There is discrete, stained fascicle out olivary complex. distal portion the facial looping visceral efferent vestibular nucleus; The most caudal neurons nucleus (heavy into the facial nucleus Counterstained with EIGHTH NERVE the facial efferent fascicle to visceral efferent distal portion the facial (heavy arrow) rected visceral efferent VISCERAL EFFERENTS OF EIGHTH NERVE Muriel D. Ross PLATE 2 467 small nu

cleus postganglionic cells the tip the ventral Slender collaterals visceral efferent inner ear into this cresyl violet. collaterals (fine the basal pale staining fascicle indicated heavy arrow nervus intermedius. nucleus are, (heavy arrows). arrow indicates a collateral from the region. pH shown along efferent fascicle pH 6.4. VISCERAL EFFERENTS OF EIGHTH NERVE Muriel D. Ross PLATE 3 469 postganglionic cells bundle are indicated heavy arrows. They reacting terminals terminals are indicated postganglionic cells The arrow indicates the axon axon; the arrows indicate ity which markedly eccentric nucleus. cresyl violet. intraganglionic spiral bundle. This few prominent 6

.4. Whole with little enzymatic reaction shown here. head pretreated the crista ampullaris positive, They VISCERAL EFFERENTS OF EIGHTH NERVE Muriel D. Ross PLATE 4 471 The macula efferent fibers, intraganglionic spiral bundle the tympanic lamina (arrow The terminal spiral limbus. VISCERAL EFFERENTS OF EIGHTH NERVE Muriel D. Ross PLATE 5 473 arrows, join from the anterior inferior are shown stained with toward the distal fine fiber, elinated segments VISCERAL EFFERENTS OF EIGHTH NERVE Muriel D. Ross PLATE 6 475 the foramen it shown here. the foramen Counterstained with about some spiral bundle; Counterstained with cresyl VISCERAL EFFERENTS OF EIGHTH NERVE Muriel