Prof. Sheng Canruo's experience in acupuncture treatment of throat diseases with yan si xue

Yan Si Xue ([symbol: see text]) refer to four points in the throat summarized by Prof. Sheng Canruo in his long-year clinical experience based on the combination of TCM theory and the knowledge of modern medical anatomy. By taking "Yan Si Xue" as main points, and other differential adjunct points, Prof. Sheng has obtained satisfactory therapeutic results in treating various throat diseases such as hoarseness, paralysis of vocal cord, dysphonia after radiotherapy on throat tumor, vocal nodules, disorder of the glossopharyngeal nerve, hysteric aphasia, and acute or chronic laryngopharyngitis.

Making rats rise to erect bipedal stance for feeding partially prevented orchidectomy-induced bone loss and added bone to intact rats

The objectives of this study were to investigate the different effects on muscle mass and cancellous (proximal tibial metaphysis [PTM]) and cortical (tibial shaft [TX]) bone mass of sham-operated and orchidectomized (ORX) male rats by making rats rise to erect bipedal stance for feeding. Specially designed raised cages (RC) were used so that the rats had to rise to erect bipedal stance to eat and drink for 12 weeks. Dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computerized tomography (pQCT) were used to estimate the lean leg mass and bone mineral. Static and dynamic histomorphometry were performed on the triple-labeled undecalcified sections. We found that making the intact rats rise to erect bipedal stance for feeding increased muscle mass, cortical bone volume, and periosteal bone formation. Orchidectomy increased net losses of bone next to the marrow by increasing bone turnover. Making the ORX rats rise to erect bipedal stance increased muscle mass, partially prevented cancellous bone loss in the PTM, and prevented net cortical bone loss in TX induced by ORX by depressing cancellous and endocortical high bone turnover and stimulating periosteal bone formation. The bone-anabolic effects were achieved mainly in the first 4 weeks in the PTM and by 8 weeks in the TX. These findings suggested that making the rats rise to erect bipedal stance for feeding helped to increase muscle mass and cortical bone mass in the tibias of intact rats, increase muscle mass, and partially prevented cancellous and net cortical bone loss in ORX rats.

Novel ligands lacking a positive charge for the delta- and mu-opioid receptors

Recently we reported using minilibraries to replace Lys(9) [somatostatin (SRIF) numbering] of the potent somatostatin agonist L-363,301 (c[-Pro-Phe-D-Trp-Lys-Thr-Phe-]) to generate the potent neurokinin receptor (NK-1) antagonist c[-Pro-Phe-D-Trp-p-F-Phe-Thr-Phe-]. This novel cyclic hexapeptide did not bind the SRIF receptor. Thus, a single mutation converted L-363,301, a SRIF agonist with potency ca. 2-8 times the potency of SRIF in laboratory animals,(24) into a selective NK-1 receptor antagonist with an IC(50) of 2 nM in vitro. During the screening of the same libraries for ligands of the delta-opioid receptor, we identified four compounds (1-4) which represent a new class of delta-opioid antagonists, some of which were also NK-1 receptor antagonists. The most potent delta-opioid antagonist, c[-Pro-1-Nal-D-Trp-Tyr-Thr-Phe-] (2), showed a K(e) value of 128 nM in the mouse vas deferens assay and a delta-receptor binding affinity constant of 152 nM in the rat brain membrane binding assay. These results are of interest because they represent a novel class of delta-opioid antagonists and, like two previously reported delta-opioid antagonists, they lack a positive charge. To examine further the requirement for a positive charge in the delta-opioid ligands, we prepared two analogues of the beta-casomorphin-derived mixed mu-agonist/delta-antagonist, H-Dmt-c[-D-Orn-2-Nal-D-Pro-Gly-] (7), in which we eliminated the positive charge either through formylation of the primary amino group (5) or by the deletion of this N-terminal amino group (6). These latter compounds proved to be delta-opioid antagonists with K(e) values in the 16-120 nM range, as well as fairly potent mu-opioid antagonists (K(e) approximately 200 nM). These six compounds provide the most convincing evidence to date that there is no requirement for a positive charge in mu- and delta-opioid receptor antagonists. In addition, cyclic hexapeptide 4 lacks a phenolic hydroxyl group. Taken together, these data suggest that the prevailing assumptions about delta- and mu-opioid receptor binding need revision and that the receptors for these opioid ligands have much in common with the NK-1 and somatostatin receptors.

Double-spin-flip resonance of rhodium nuclei at positive and negative spin temperatures

Sensitive SQUID-NMR measurements were used to study the mutual interactions in the highly polarized nuclear-spin system of rhodium metal. The dipolar coupling gives rise to a weak double-spin-flip resonance. The observed frequency shifts allow deducing separately the dipolarlike contribution and the isotropic exchange term. For the first time, such measurements were extended to negative absolute temperatures as well. We find an effective dipolar moment 0. 10&mgr;(N) of which about 15% is attributed to a conduction electron mediated pseudodipolar interaction. The isotropic exchange is described by R = -0.9+/-0.1.

Motor-unit synchronization increases EMG amplitude and decreases force steadiness of simulated contractions

The purpose of the study was to determine the effect of motor-unit synchronization on the surface electromyogram (EMG) and isometric force using a computer model of muscle contraction. The EMG and force were simulated by generating muscle fiber action potentials, defining motor-unit mechanical characteristics and territories, estimating motor-unit action potentials, specifying motor-unit discharge times, and imposing various levels of motor-unit synchronization. The output (EMG and force) was simulated at 11 levels of excitation, ranging from 5 to 100% of maximum. To synchronize motor-unit activity, selected motor-unit discharge times were adjusted; however, the number of motor units recruited and the average discharge rate of each unit was constant across synchronization conditions for a given level of excitation. Two levels of synchronization were imposed on the discharge times: a moderate and a high level, which approximated the experimentally observed range of motor-unit synchronization. The moderate level of synchrony caused the average EMG to increase by approximately 65%, whereas the high level caused a 130% increase in the EMG with respect to the no-synchrony condition. Neither synchrony condition influenced the magnitude of the average force. However, motor-unit synchronization did increase the amplitude of the fluctuations in the simulated force, especially at intermediate levels of excitation. In conclusion, motor-unit synchronization increased the amplitude of the average rectified EMG and decreased the steadiness of the force exerted by the muscle in simulated contractions.

Anabolic effect of prostaglandin E2 on cortical bone of aged male rats comes mainly from modeling-dependent bone gain

In this study, prostaglandin E2 (3 mg/kg per day) was administered to 20-month-old male Wistar rats for 10 and 30 days. Histomorphometric analyses were performed on double-fluorescent-labeled undecalcified tibial shaft sections. Thirty days of prostaglandin E2 (PGE2) administration increased bone formation rate/total bone surface from undetectable levels to 0.6 microm/day at the periosteal surface and from 0.5 to 2.1 microm/day at the endocortical surface. Endocortical osteoid surface area increased from 2% to 67% at day 10 and decreased to 6% at day 30; woven and lamellar bone formation started at day 0, but was most obvious at day 30, resulting in a 12% increase of total bone mass. The red to yellow marrow ratio was 0.2 in pretreatment controls, and increased to 1.6 by day 10 and 2.4 by day 30 with PGE2 administration. Intracortical cavity number and area increased after 10 days of PGE2 treatment, but with forming osteon number and area far exceeding those of resorption cavities at day 30. Endocortical modeling surface/endocortical surface was only 1.5%, and remodeling was 11.1% in pretreatment controls. PGE2 treatment increased modeling to 24.5% in the 10 day group and 93.7% in the 30 day group, whereas remodeling remained unchanged at 10 days, and decreased to 6.2% at 30 days. Osteoprogenitor cells and osteoblasts could not be detected in pretreatment controls, but increased by day 10, and returned almost to control levels by 30 days. Our data indicate that PGE2 induced periosteal and endocortical bone formation mainly by modeling-dependent bone gain, accompanied by increases in intracortical remodeling and red bone marrow, and a transient increase in the osteoprogenitor cells adjacent to the endocortical surface. These findings suggest that 20-month-old male Wistar rats were very responsive to the anabolic action of PGE2 in the tibial shaft, a site consisting mainly of cortical bone and yellow marrow.

Cloning and first functional characterization of a plant cyclic nucleotide-gated cation channel

Cyclic nucleotide-gated (cng) non-selective cation channels have been cloned from a number of animal systems. These channels are characterized by direct gating upon cAMP or cGMP binding to the intracellular portion of the channel protein, which leads to an increase in channel conductance. Animal cng channels are involved in signal transduction systems; they translate stimulus-induced changes in cytosolic cyclic nucleotide into altered cell membrane potential and/or cation flux as part of a signal cascade pathway. Putative plant homologs of animal cng channels have been identified. However, functional characterization (i.e. demonstration of cyclic-nucleotide-dependent ion currents) of a plant cng channel has not yet been accomplished. We report the cloning and first functional characterization of a plant member of this family of ion channels. The Arabidopsis cDNA AtCNGC2 encodes a polypeptide with deduced homology to the alpha-subunit of animal channels, and facilitates cyclic nucleotide-dependent cation currents upon expression in a number of heterologous systems. AtCNGC2 expression in a yeast mutant lacking a low-affinity K(+) uptake system complements growth inhibition only when lipophilic cyclic nucleotides are present in the culture medium. Voltage clamp analysis indicates that Xenopus laevis oocytes injected with AtCNGC2 cRNA demonstrate cyclic-nucleotide-dependent, inward-rectifying K(+) currents. Human embryonic kidney cells (HEK293) transfected with AtCNGC2 cDNA demonstrate increased permeability to Ca(2+) only in the presence of lipophilic cyclic nucleotides. The evidence presented here supports the functional classification of AtCNGC2 as a cyclic-nucleotide-gated cation channel, and presents the first direct evidence (to our knowledge) identifying a plant member of this ion channel family.

[Studies on male reproductive toxicity caused by hexavalent chromium]

OBJECTIVE

To study male reproductive toxicity caused by hexavalent chromium (Cr(VI +)).

METHODS

Morphology of semen and spermatozoa was observed and chromium level in blood, chromium and zinc level in sperm plasma, leuteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in serum were determined for male workers exposed to (Cr(VI +)) (CrO(3)X = 0.0195 mg/m(3)) with occupational epidemiologic investigation and laboratory analysis.

RESULTS

For the exposed workers, their seminal counting was (52.21 +/- 45.51) x 10(9)/L, and zinc level in seminal plasma (4,811.85 +/- 1,401.88) micromol/L, significantly lower than those in controls (88.96 +/- 74.82) x 10(9)/L and (5 718.49 +/- 2 827.90) micromol/L, respectively, P < 0.05. Serum FSH was (7.34 +/- 6.88) IU/L in the exposed groups, significantly higher than that of controls (2.41 +/- 1.69) IU/L, P < 0.01. There were no significant difference in semen volume, semen liquefaction time, prevalence of teratospermia, serum Cr(VI +) and LH level in seminal plasma between exposed group and control group (P > 0.05). Prevalence of teratospermia was 0.24 +/- 0.09, and serum LH and FSH were (7.94 +/- 2.67) IU/L and FSH (9.33 +/- 6.47) IU/L, respectively, in workers exposed to high concentration of Cr(VI +) (CrO(3)X = 0.2351 mg/m(3)) significantly higher than those exposed to lower concentration of Cr(VI +) (CrO(3)X = 0.0172 mg/m(3)), with 0.17 +/- 0.06 of prevalence of teratospermia, (5.05 +/- 3.05) IU/L of LH, and (3.74 +/- 3.04) IU/L of FSH, respectively (P < 0.05).

CONCLUSION

The results suggested that damage to convoluted seminiferous tubules epithelium, reduction of spermatozoa formation and increase in prevalence of teratospermia could be caused by exposure to certain concentration of Cr(VI +).

[Effects of Rg1 on calcium channel of guinea pig ventricular myocytes]

OBJECTIVE

To evaluate the effect of Rg1 (purified saponin of Panax notoginseng) on L-Ca2+ channel of guinea pig ventricular myocytes.

METHOD

The whole-cell patch clamp recording technique.

RESULT

When the holding potential was kept at -40 mV, and the cell was depolarized to +40 mV for 150 ms at a frequency of 0.5 Hz.Rg1 10 mumol.L-1 and 30 mumol.L-1 could not reduce Bay K 8644 and nifedipine-sensitive L-type Ca2+ inward current (P > 0.05, n = 5).

CONCLUSION

Rg1 should not be a Ca2+ channel antagonist.

[Arterial infusion chemotherapy combined with concurrent radiotherapy for local advanced pancreatic cancer]

OBJECTIVE

To analyze the treatment results of un-resectable local pancreatic cancer by arterial infusion chemotherapy plus concurrent radiotherapy or radiotherapy alone.

METHODS

A total of 50 patients with local advanced pancreatic cancer from January 1992 through October 1995 were treated either by arterial infusion chemotherapy (C) plus concurrent radiotherapy (R) (22 cases) or by radiotherapy alone (28 cases). Radiation given was the same in the two groups of patients (50-60 Gy in 5 to 6 weeks, 1.8-2 Gy/Fx, 5 Fx/wk). Infusion chemotherapy was performed once every 4 weeks, consisting of 5-fluorouracil 1.0 g, mitomycin C 10 mg, cisplatin 60 mg. An average of 2.3 cycles was given to each patient.

RESULTS

Although the remission rate of jaundice and pain did not show significant difference between the two groups, patients in C + R treatment group had longer period of symptomatic remission (P < 0.05). The response rate (CR + PR) was 68.2% in C + R treatment group and 35.7% in R treatment group, respectively. The 1-, 2-, and 3-year survival rate was 75.3%, 36.8%, 25.4% in C + R treatment group, and 51.3%, 22.6%, 8.7% in R treatment group, respectively.

CONCLUSION

Arterial infusion chemotherapy combined with concurrent radiotherapy is a treatment of choice for patients with local unresectable cancer of the pancreas.

[Molecular cloning of rat OB gene and its expression in Escherichia coli]

In order to provide rat OB gene product for studying the relationship between obesity and noninfectious diseases, rat OB cDNA was amplified by RT-PCR technique. 460 bp fragment of OB cDNA was subcloned into EcoRI/BamHI site of plasmid pUC 19. Sequence analysis of OB cDNA revealed that the translation reading frame was identical with that reported in the literature. Thereby plasmid pBV220-rOB was constructed and the specific expression of OB gene in E. coli identified by SDS-PAGE electrophoresis was obtained.

Late course accelerated fractionation in radiotherapy of esophageal carcinoma

PURPOSE

To evaluate the efficacy of adding accelerated fractionation after completing two thirds of routine fractionated radiotherapy in esophageal carcinoma.

METHODS AND MATERIALS

From April 1988 to April 1990, 85 patients with histologically confirmed carcinoma of the esophagus were randomized into two groups. (1) The conventional fractionation (CF) group, received 1.8 Gy per day five times a week to a total dose of 68.4 Gy in 7-8 weeks, and (2) the late course accelerated hyperfractionated (LCAF) group which received the same schedule as the CF group during the first two thirds of the course of radiotherapy to a dose of 41.4 Gy/23 fx/4 to 5 weeks. This was then followed by accelerated hyperfractionation using reduced fields. In the LCAF portion of the radiotherapeutic course, the irradiation schedule was changed to 1.5 Gy twice a day, with an interval of 4 h between fractions, to a dose of 27 Gy/18 fx. Thus the total dose was also 68.4 Gy, the same as the CF group, but the course of radiotherapy was shorter, being only 6.4 weeks. The same Cobalt 60 teletherapy unit was used to treat all the cases.

RESULTS

The 5 year actuarial survival and disease-free survival rates in the LCAF group were 34% and 42%, as compared to 15% and 15% respectively in the CF group, all statistically significant. Better local control was seen in the LCAF group than in the CF group, the 5 year control rates being 55% versus 21% (P = 0.003). The acute reactions were increased but acceptable in the LCAF patients, the radiation treatments could be completed without any breaks. The late reactions as observed after 5 years were not increased in comparison with the CF patients.

CONCLUSIONS

The results from this study show that the late course accelerated hyperfractionated radiotherapy regime can improve results in esophageal carcinoma, with acceptable acute reactions as compared to conventional radiotherapy.

Immunolocalization of alpha4 and alpha7 subunits of nicotinic receptor in rat cochlear nucleus

The rat cochlear nucleus (CN) is known to receive cholinergic input. To investigate the prevalence of nicotinic acetylcholine receptor (nAChR), immunohistochemistry for alpha4 and alpha7 subunits, which represent nAChRs with high binding affinities for nicotine and alpha-bungarotoxin, respectively, was performed on perfusion-fixed rat brain sections. Microscopic observations and densitometric measurements show dense labeling for alpha7 but not alpha4. Within the CN, alpha7 receptors are found in all subregions, with relatively high densities in granular regions. The distribution of alpha7 within the CN appears to correlate more closely with that of acetylcholinesterase than with mAChR or choline acetyltransferase. Our results suggest a role of nicotinic cholinergic transmission in the rat CN associated with high affinity for alpha-bungarotoxin.

[The effect of inhaled ipratropium bromide on airway and lung tissue muscarinic receptors in a rat model of COPD]

OBJECTIVE

To observe the effect of inhaled ipratropium bromide on airway and lung tissue muscarinic receptors (MR) in a rat model of chronic obstructive pulmonary disease (COPD).

METHODS

The rat model of COPD was established by chronic exposure with high concentrations of SO(2) gas, COPD rats inhaled aerosolized 0.025% ipratropium bromide solution 10 ml (twice/d, 20min/time). The MR was determined by radioligand binding studies with (3)H-QNB as the ligand.

RESULTS

Compared with that of control, there was a marked increase in MR density on day 30 of treatment with ipratropium but not on day 5. The MR density decreased and close to normal level on the 6th day after cessation of regular therapy with inhaled ipratropium for 30 days. No significant difference was observed in antagonist affinity (Kd) among different time groups of ipratropium therapy.

CONCLUSIONS

Chronic exposure to the anticholinergic agent ipratropium bromide produces an up-regulation of airway MR. The airway MR density can recover to normal when treatment stopped. Up-regulation of airway MR is associated with transient bronchoconstriction following cessation of regular ipratropium therapy and lung function deteriorated following long-term inhaled ipratropium bromide.

[The effects of inhaled bronchodilators on central inspiratory drive in patients with COPD]

OBJECTIVE

To evaluate the effects of inhaled bronchodilators on the central inspiratory drive in patients with COPD.

METHODS

91 patients with COPD were divided into three groups (A, B, C) randomly. Lung functions and P(0.1) were measured at baseline and 20 min and 60 min after inhalation (A: albuterol; B: iprotropium; C: albuterol + iprotropium).

RESULTS

P(0.1) decreased after inhalation in all three groups (P < 0.05 approximately 0.001). A positive correlation between DeltaP(0.1) and DeltaFRC was found in the three groups (r = 0.4325 - 0.5230, P < 0.05 approximately 0.01). V(E)/P(0.1) increased in the three groups after inhalation (P < 0.05 approximately 0.005). There was significant improvement of V(E)/P(0.1) in group B and C as compared with that of group A (P < 0.05, P < 0.001); There was a different correlative factor with V(E)/P(0.1) in group B and C.

CONCLUSIONS

(1) P(0.1) decreased after inhalation, It may be caused by decreased FRC. (2) V(E)/P(0.1) became appropriate after inhalation in all groups; The improvement in group B and C was superior to that of group A. There may be different mechanisms to improve V(E)/P(0.1) by different inhalators.

Vesicular acetylcholine transporter in the rat cochlear nucleus: an immunohistochemical study

After being synthesized in the cytoplasm of axon terminals, acetylcholine is packaged into synaptic vesicles by a proton-dependent transporter, vesicular acetylcholine transporter (VAChT). Localization of VAChT is restricted to cholinergic neurons, especially their terminals. We used an anti-VAChT antibody from INCSTAR to localize cholinergic terminals in the rat cochlear nucleus (CN), an important brainstem auditory center. VAChT immunoreactivity in the rat CN appears as labeled puncta and a few connecting fibers. In ventral CN (VCN), VAChT-labeled puncta are closely associated with somatic profiles of medium to large neurons. In and near the granular regions of VCN, VAChT-labeled puncta are more diffusely scattered. In the subpeduncular corner and the medial sheet, some VAChT-labeled fibers are seen in connection with especially prominent VAChT-labeled puncta. In dorsal CN (DCN), VAChT-labeled puncta show no clear association with somata and are found in all layers. Ultrastructurally, VAChT labeling is seen in the cytoplasm and is associated with synaptic vesicle membrane of terminals with small round vesicles. Such VAChT-labeled terminals synapse with cell bodies and dendrites in the CN.(J Histochem Cytochem 47:83-90, 1998)

[Effects of inhalated isosorbide dinitrate on endothelin and nitric oxide and its therapeutic efficacy for experimental guinea-pigs with asthma]

To probe into the correlation between the changes of endothelin and nitric oxide in bronchial alveolar lavage fluid (BALF) and the treatment of inhaling isosorbide dinitrate on experimental guinea pigs with asthma, we divided 25 guinea pigs randomly into three groups (Control group, Asthma group, Isosorbide dinitrate group), and induced some subjects by inhalation of aerosolized ovalbumin as the model of asthma to investigate the endothelin (ET) and nitric oxide (NO) level in BALF as well as the pathological change of the respiratory tract. We found that the level of endothelin and nitric oxide in BALF were all elevated in experimental guinea pigs with asthma, but the degree of increase of NO in BALF was lower than that of ET. The NO and the ET levels in BALF were negative correlation (r = -0.8050, P < 0.01). After having been treated with aerosolized isosorbide dinitrate, the NO level in BALF was significantly elevated and the ET level in BALF was decreased in comparison with the asthma group (P < 0.001, respectively). Moreover, the eosinophile infiltration, exoserosis, and epithalaxia of the respiratory tract of the guinea-pigs were all lightened. The results suggest that inhaled isosoratory dinitrate could be used for treating asthma, and its mechanism may be elevation of NO level and decrease of ET level in BALF.

Transport characteristics of peptidomimetics. Effect of the pyrrolinone bioisostere on transport across Caco-2 cell monolayers

PURPOSE

To compare the permeation characteristics of amide bond-containing HIV-1 protease inhibitors and their pyrrolinone-containing counterparts across Caco-2 cell monolayers, a model of the intestinal mucosa.

METHODS

Transepithelial transport and cellular uptake of three pairs of amide bond-containing and pyrrolinone-based peptidomimetics were assessed in the presence and absence of cyclosporin A using the Caco-2 cell culture model. The potential of the peptidomimetics to interact with biological membranes was estimated by IAM chromatography.

RESULTS

In the absence of cyclosporin A, apical (AP) to basolateral (BL) flux of all compounds studied was less than the flux determined in the opposite direction (i.e., BL-to-AP). The ratio of the apparent permeability coefficients (Papp) calculated for the BL-to-AP and AP-to-BL transport (P(BL-->AP)/P(AP-->BL)) varied between 1.7 and 36.2. When individual pairs were ompared, P(BL-->AP)/P(AP-BL) ratios of the pyrrolinone-containing compounds were 1.5 to 11.5 times greater than those determined for the amide bond-containing analogs. Addition of 25 microM cyclosporin A to the transport buffer reduced the P(BL-->AP)/P(AP-->BL) ratios for all protease inhibitors to a value close to unity. Under these conditions, the amide bond-containing peptidomimetics were at least 1.6 to 2.8 times more able to permeate Caco-2 cell monolayers than were the pyrrolinone-containing compounds. The intrinsic uptake characteristics into Caco-2 cells determined in the presence of 25 microM cyclosporin A were slightly greater for the amide bond-containing protease inhibitors than for the pyrrolinone-containing analogs. These uptake results are consistent with the transepithelial transport results determined across this in vitro model of the intestinal mucosa.

CONCLUSIONS

The amide bond-containing and pyrrolinone-based peptidomimetics are substrates for apically polarized efflux systems present in Caco-2 cell monolayers. The intrinsic permeabilities of the amide bond-containing protease inhibitors are slightly greater than the intrinsic permeabilities of the pyrrolinone-based analogs through Caco-2 cell monolayers.

Immunohistochemical evaluation of cholinergic neurons in the rat superior olivary complex

The cholinergic system in the rat superior olivary complex (SOC) was evaluated by immunohistochemistry for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) and histochemistry for acetylcholinesterase (AChE). ChAT-positive somata were found mostly in the lateral superior olive (LSO) and ventral nucleus of the trapezoid body (VNTB). In the LSO, there were both rostral-caudal and medial-lateral gradients in concentration of ChAT-positive somata; the highest concentration was in the middle of the rostral-caudal extent and the most medial part. The estimated total number of ChAT-positive neurons in the LSO was similar to previous estimates of the total number of lateral olivocochlear neurons. Two groups of ChAT-positive somata were found in the VNTB: a dorsolateral group of larger, multipolar, and more darkly labeled neurons and a ventromedial group of smaller, oval, and more lightly labeled neurons, which was about 5 times as numerous. There was a caudal-to-rostral increase in number of neurons in each group. VAChT immunoreactivity, predominantly localized in puncta, was seen in LSO, VNTB, and LNTB, and, to a lesser extent, in other parts of the SOC. VAChT-positive somata were also found in the VNTB and medial LSO. This distribution pattern of VAChT was generally similar to that of ChAT. AChE labeling had a similar appearance to ChAT labeling in the VNTB but differed in the LSO, where AChE labeling was lighter and associated more with neuropil than with somata.