Identification of sex-specific polymorphic sequences in the goat amelogenin gene for embryo sexing

Amelogenin (AMEL) is a conserved gene located on the sex chromosomes of mammals. It is involved in the formation of enamel, which is the hard, white material that forms the protective outer layer of each tooth. In this study, we first cloned and determined the intron sequences of the goat AMELX and AMELY genes from female and male ear tissues. The polymorphic AMEL alleles were further analyzed by PCR-based RFLP and Southern blot hybridization analyses. Results showed that intron 5 nucleotide sequences of the goat AMELY gene contains multiple deletions/insertions and shares only 48.5% identity to intron 5 of the goat AMELX gene. Based on the polymorphic AMEL intron sequences, a set of sex-specific triplex primers was designed to PCR amplify a single fragment of 264 bp from the X chromosome of female goats and 2 fragments of 264 and 206 bp from the X and Y chromosomes, respectively, of male goats. An increased sensitivity for sex determination was reached with a single blastomere at the blastula stage isolated from goat embryos. A total of 43 goat embryos were used to estimate a 100% accuracy rate of this method confirmed by chromosomal karyotyping and live births. The embryo sexing technique has been successfully applied in different strains of goats including Alpine, Saanen, Nubian, and Taiwan goats.

Application of high-frequency ultrasound for the detection of surgical anatomy in the rodent abdomen

Rats are used extensively in abdominal disease research. To monitor disease progress in vivo, high-frequency ultrasound (HFU) can be a powerful tool for obtaining high-resolution images of biological tissues. However, there is a paucity of data regarding the correlation between rat anatomy and corresponding HFU images. Twenty-four adult male Sprague-Dawley (SD) rats underwent abdominal scans using HFU (40 MHz) surgical procedures to identify abdominal organs and major vessels as well as in situ scanning to confirm the imaging results. The results were compared with those of human abdominal organs in ultrasonographic scans. The rat liver, paired kidneys, stomach, intestines, and major blood vessels were identified by HFU and the ultrasonic morphologies of the liver and kidneys showed clear differences between rats and humans. Clinically relevant anatomical structures were identified using HFU imaging of the rat abdomen, and these structures were compared with the corresponding structures in humans. Increased knowledge with regard to identifying the anatomy of rat abdominal organs by ultrasound will allow scientists to conduct more detailed intra-abdominal research in rodents.

Development and validation of an improved Bradford method for determination of insulin from chitosan nanoparticulate systems

CONTEXT

Blank chitosan nanoparticles are currently used as reference for the calibration curve, which fails to resolve the supernatant of the nanoparticles in the interference of Coomassie Brilliant Blue G-250 reagent; supernatants are generated at different chitosan nanoparticulate prescriptions, which have different interferences. There are notable errors in the experimental results, and the method is not feasible.

OBJECTIVE

In this study, an improved, rapid, and economic Bradford method was developed and validated.

MATERIALS AND METHODS

The pH of the supernatant of blank chitosan nanoparticles was adjusted to 7-9 through adding saturated NaOH. The precipitation (free chitosan) in the solution was separated by centrifuging for about 10 min (4000 r/min).

RESULTS

The method eliminated the interference of free chitosan of different prescriptions. The results showed that the method presented a linearity in the range of 50-300 microg/mL (R(2) = 0.9992), and possessed a good inter-day and intra-day precision based on relative standard deviation values (less than 3.10%). Recovery of the supernatant of blank chitosan nanoparticles was between 98.30 and 99.93%, and the recovery of blank chitosan nanoparticles was between 95.57 and 100.27%.

DISCUSSION AND CONCLUSION

The method was further tested for determination of the association efficiency of insulin to nanoparticulate carriers composed of chitosan. Encapsulant release under simulated gastrointestinal fluids was evaluated.

Simultaneous detection of multiple-gas species by correlation spectroscopy using a multimode diode laser

Simultaneous detection of multiple-gas species has for the first time (to our knowledge) been demonstrated by using a multimode diode-laser-based correlation spectroscopy (MDL-COSPEC) scheme. Concentration measurements of a mixture of CO(2) and CO gas were performed by probing overlapping line spectra around 1.57microm using an MDL. Species identification and corresponding quantitive analysis were implemented by correlating the recorded absorption signals of the sample gas mixtures with those of the reference gases of particular interest, attaining accuracies of 2% and 1%, respectively. MDL-COSPEC is a generic technique with potential application for simultaneous detection of multiple gases having resolvable narrow lines.

The physiological role of pre- and postsynaptic GABA(B) receptors in membrane excitability and synaptic transmission of neurons in the rat's dorsal cortex of the inferior colliculus

In the inferior colliculus (IC), GABAergic inhibition mediated by GABA(A) receptors has been shown to play a significant role in regulating physiological responses, but little is known about the physiological role of GABA(B) receptors in IC neurons. In the present study, we used whole-cell patch clamp recording in vitro to investigate the effects of activation of GABA(B) receptors on membrane excitability and synaptic transmission of neurons in the rat's dorsal cortex of the inferior colliculus (ICD). Repetitive stimulation of GABAergic inputs to ICD neurons at high frequencies could elicit a slow and long-lasting postsynaptic response, which was reversibly abolished by the GABA(B) receptor antagonist, CGP 35348. The results suggest that postsynaptic GABA(B) receptors can directly mediate inhibitory synaptic transmission in ICD. The role of postsynaptic GABA(B) receptors in regulation of membrane excitability was further investigated by application of the GABA(B) receptor agonist, baclofen. Baclofen hyperpolarized the cell, reduced the membrane input resistance and firing rate, increased the threshold for generating action potentials (APs), and decreased the amplitude of the AP and its associated after-hyperpolarization. The Ca2+-mediated rebound depolarization following hyperpolarization and the depolarization hump at the beginning of membrane depolarization were also suppressed by baclofen. In voltage clamp experiments, baclofen induced inward rectifying K+ current and reduced low- and high-threshold Ca2+ currents, which may account for the suppression of membrane excitability by postsynaptic GABA(B) receptors. Application of baclofen also reduced excitatory synaptic responses mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and inhibitory synaptic responses mediated by GABA(A) receptors. Baclofen increased the ratios of 2nd/1st excitatory and inhibitory postsynaptic currents to paired-pulse stimulation of the synaptic inputs. These results suggest that fast glutamatergic and GABAergic synaptic transmission in ICD can be modulated by presynaptic GABA(B) receptors.

Baculovirus-derived hemagglutinin vaccine protects chickens from lethal homologous virus H5N1 challenge

Since outbreaks of highly pathogenic avian influenza (HPAI) in both human and poultry from 2003, it is critical to have effective vaccines. A cDNA fragment coding the entire hemagglutinin (HA) gene derived from an H5N1 strain (A/duck/China/E319-2/03) was cloned and expressed using the baculovirus system. Two weeks after receiving two doses of recombinant HA (rHA) vaccines, chickens develop high antibody response for hemagglutination inhibition (HI) at titer 7.2 log(2). Challenge studies revealed that vaccinated chickens with HI titers greater than 3 log(2) could have immunoprotection against the same HPAI H5N1 strain virus challenge through intranasal route. Additionally, HI titer of 5 log(2) determined whether the live viruses could not be detected from oropharyngeal, cloacal discharge or in tissues. This result suggests that the rHA expressed from baculovirus system could be a candidate for the development of a safe and efficient subunit vaccine for HPAI (H5N1).

Modification of membrane excitability of neurons in the rat's dorsal cortex of the inferior colliculus by preceding hyperpolarization

The inferior colliculus (IC) is among the largest nuclei in the central auditory system and is considered to be a major integration center in the auditory pathway. To understand how IC contributes to auditory processing, we investigated the effects of preceding hyperpolarization on membrane excitability and firing behavior of neurons located in the dorsal cortex of the inferior colliculus (ICD). We made whole-cell patch clamp recordings from ICD neurons (n=96) in rat brain slices. We classified ICD neurons into three types, i.e. sustained-regular, sustained-adapting and buildup, according to their responses to depolarizing current injection. Nearly 91% of the neurons had sustained firing throughout the period of current injection, showing either regular or adapting pattern. About 9% of the neurons exhibited a buildup pattern, in which sustained firing started after a long delay. Rebound depolarization and spikes after hyperpolarization were seen in 51.7% of the sustained neurons, but were not seen in buildup neurons. When depolarizing current was preceded by a hyperpolarizing current, various forms of the modification on membrane excitability were observed. For non-rebound neurons, the membrane excitability was either suppressed or unchanged after pre-hyperpolarization. The first spike latency lengthened in neurons whose firing changed to a buildup pattern, shortened in those whose firing changed to a pauser pattern, and remained unchanged in those whose discharge pattern remained sustained. For rebound neurons, the firing rate decreased in neurons whose firing pattern was changed to onset or pauser, increased in neurons whose firing was changed to adapting, or remained unchanged in neurons whose firing became irregular. The first spike latency was shortened in all the rebound cells. The results suggest that intrinsic membrane properties can play an important role in integration of excitatory and inhibitory inputs and thereby in determination of the output of ICD neurons.

Sesquiterpene lactones from Saussurea alata

Two new guaianolides, namely, 3beta,8alpha-dihydroxy-13-methoxyl-4(14),10(15)-dien-(1alphaH,5alphaH,6beta H,11betaH)-12,6-olide (1) and 3beta,8alpha-dihydroxy-13-methoxyl-4(14),10(15)-dien-(1alphaH,5alphaH,6beta H,11alphaH)-12,6-olide (2), together with six known guaianolides, 8-hydroxyzaluzanin C, austricin, chlorojanerin, cynaropicrin, chlorohyssopifolin E and chlorohyssopifolin A were isolated from the aerial parts of Saussurea alata. The structures were established mainly based on spectral analysis, especially 2D NMR techniques.

Neurotrophin signaling: many exciting surprises!

Neurotrophins are growth factors implicated in the development and maintenance of different neuronal populations in the nervous system. Neurotrophins bind to two sets of receptors, Trk receptor tyrosine kinases and the p75NTR receptor, to activate several different signaling pathways that mediate various biological functions. While Trk receptor activation has been well-studied and triggers the well-characterized Ras/Rap-MAPK, PI3K-Akt, and PLCgamma-PKC cascades, p75NTR signaling is more complex, and its in vivo significance has not yet been completely determined. In the last few years, p75NTR has received much attention mainly due to recent findings describing pro-neurotrophins as new ligands for the receptor and the ability of the receptor to form different complexes with other transmembrane proteins. This review will update the neurotrophin signaling pathways known for Trk receptors to include newly identified Trk-interacting molecules and will address surprising new findings that suggest a role for p75NTR in different receptor complexes and functions.

CeO2 Nanorods and Gold Nanocrystals Supported on CeO2 Nanorods as Catalyst

The formation mechanism of uniform CeO2 structure at the nanometer scale via a wet-chemical reaction is of great interest in fundamental study as well as a variety of applications. In this work, large-scale well-crystallized CeO2 nanorods with uniform diameters in the range of 20-30 nm and lengths up to tens of micrometers are first synthesized through a hydrothermal synthetic route in 5 M KOH solution at 180 degrees C for 45 h without any templates and surfactants. The nanorod formation involves dehydration of CeO2 nanoparticles and orientation growth along the 110 direction in KOH solution. Subsequently, gold nanoparticles with crystallite sizes between 10 and 20 nm are loaded on the surface of CeO2 nanorods using HAuCl4 solution as the gold source and NaBH4 solution as a reducing agent. The synthesized Au/CeO2 nanorods demonstrate a higher catalytic activity in CO oxidation than the pure CeO2 nanorods.

Presynaptic modulation of GABAergic inhibition by GABA(B) receptors in the rat's inferior colliculus

Whole-cell patch clamp recordings were made from neurons in a brain slice preparation of the inferior colliculus in 11-15-day-old rat pups. Synaptic responses were elicited by applying a current pulse to the lateral lemniscus just below the central nucleus of the inferior colliculus. To examine GABAergic inhibition in the inferior colliculus all excitatory postsynaptic potentials and glycinergic inhibitory postsynaptic potentials were blocked by bath application of their respective antagonists and the contribution of GABA(B) receptors was determined for the remaining inhibitory postsynaptic potentials. For most cells the isolated inhibitory postsynaptic potential was completely blocked by the GABA(A) receptor antagonist, bicuculline, but was unaffected by the GABA(B) receptor antagonist, phaclofen. The GABA(B) receptor agonist, baclofen (10-20 microM), decreased the amplitude of the inhibitory postsynaptic potentials. This effect was completely blocked by phaclofen. Baclofen did not increase the cell membrane conductance or alter the rate of firing produced by depolarization of the cell membrane. In contrast, muscimol, a GABA(A) receptor agonist, greatly increased membrane conductance and lowered the firing rate produced by depolarization. Our results indicate that GABAergic inhibition in the auditory midbrain can be reduced by the activation of GABA(B) receptors and suggest that the effects are presynaptic.

Genotype and allele frequency of the 27-bp tandem repeat polymorphism in the endothelial nitric oxide synthase gene in Chinese population

Genotype and allele frequency of the polymorphic 27-bp repeat, a variable number of tandem repeats (VNTR) located in intron 4 of the endothelial nitric oxide synthase gene, were analyzed in 316 healthy Chinese individuals. Four genotypes, namely 6/5-repeats heterozygous, 5/5-repeats homozygous, 5/4-repeats heterozygous and 4/4-repeats homozygous, were identified. Both observed genotype and allele frequencies of this VNTR in Chinese were similar to those of Japanese, while the 4/4-repeats genotype differed significantly from that of Caucasians in Spain, and all ones did from those of African-American in United States.

Symmetrical body-weight distribution training in stroke patients and its effect on fall prevention

OBJECTIVE

To determine the role of symmetrical body-weight distribution training in preventing falls among patients with hemiplegic stroke.

DESIGN

A prospective study using a standing biofeedback trainer.

SETTING

Hospital-based rehabilitation units.

PATIENTS

Fifty-four patients with hemiplegic stroke (30 in the training group, 24 in the control group).

INTERVENTIONS

Conventional stroke rehabilitation program, plus symmetrical standing training and repetitive sit-to-stand training, with a standing biofeedback trainer. Training effect was evaluated by assessing the sit-to-stand performance and comparing the occurrence of falls in the 2 groups at a 6-month follow-up.

MAIN OUTCOME MEASURES

Occurrence of falls, sit-to-stand performance, including body-weight distribution, rate of rise in force, and sway in center of pressure (COP).

RESULTS

Significant improvement in sit-to-stand performance was found in patients in the training group. Body weight was distributed more symmetrically in both legs, with less mediolateral sway in the COP when rising and sitting down. The mean difference in body-weight distribution between the left and right legs while subjects were rising from a chair significantly decreased, from 49.5% +/- 18.9% to 38.6% +/- 15.8% of body weight (BW) (p < .005). The rate of rise in force while rising from a chair significantly increased, from 28.3% +/- 13.5%BW/s to 53.6% +/- 20.5%BW/s (p < .001). At the 6-month follow-up, 10 of 24 patients (41.7%) in the control group had fallen, compared with only 5 of 30 patients (16.7%) in the training group (p < .05).

CONCLUSIONS

Symmetrical body-weight distribution training may improve sit-to-stand performance and, consequently, decrease the number of falls by stroke patients.

Cloning, sequencing, heterologous expression, purification, and characterization of adenosylcobalamin-dependent D-ornithine aminomutase from Clostridium sticklandii

D-Ornithine aminomutase from Clostridium sticklandii catalyzes the reversible rearrangement of d-ornithine to (2R,4S)-2,4-diaminopentanoic acid. The two genes encoding d-ornithine aminomutase have been cloned, sequenced, and expressed in Escherichia coli. The oraS gene, which encodes a protein of 121 amino acid residues with M(r) 12,800, is situated upstream of the oraE gene, which encodes a protein of 753 amino acid residues with M(r) 82,900. The holoenzyme appears to comprise a alpha(2)beta(2)-heterotetramer. OraS shows no significant homology to other proteins in the Swiss-Prot data base. The deduced amino acid sequence of OraE includes a conserved base-off/histidine-on cobalamin-binding motif, DXHXXG. OraE was expressed in E. coli as inclusion bodies. Refolding experiments on OraE indicate that the interactions between OraS and OraE and the binding of either pyridoxal phosphate or adenosylcobalamin play important roles in refolding process. The K(m) values for d-ornithine, 5'-deoxyadenosylcobalamin (AdoCbl), and pyridoxal 5'-phosphate (PLP) are 44.5 +/- 2.8, 0.43 +/- 0.04, and 1.5 +/- 0.1 microm, respectively; the k(cat) is 6.3 +/- 0.1 s(-1). The reaction was absolutely dependent upon OraE, OraS, AdoCbl, PLP, and D-ornithine being present in the assay; no other cofactors were required. A red-shift in UV-visible absorption spectrum is observed when free adenosylcobinamide is bound by recombinant D-ornithine aminomutase and no significant change in spectrum when free adenosylcobinamide is bound by mutant OraE-H618G, demonstrating that the enzyme binds adenosylcobalamin in base-off/histidine-on mode.

Solution structure of a Kunitz-type chymotrypsin inhibitor isolated from the elapid snake Bungarus fasciatus

Bungarus fasciatus fraction IX (BF9), a chymotrypsin inhibitor, consists of 65 amino acid residues with three disulfide bridges. It was isolated from the snake venom of B. fasciatus by ion-exchange chromatography and belongs to the bovine pancreatic trypsin inhibitor (BPTI)-like superfamily. It showed a dissociation constant of 5.8 x 10(-8) m with alpha-chymotrypsin as measured by a BIAcore binding assay system. The isothermal titration calorimetry revealed a 1:1 binding stoichiometry between this inhibitor and chymotrypsin and apparently no binding with trypsin. We further used CD and NMR to determine the solution structure of this venom-derived chymotrypsin inhibitor. The three-dimensional NMR solution structures of BF9 were determined on the basis of 582 restraints by simulated annealing and energy minimization calculations. The final set of 10 NMR structures was well defined, with average root mean square deviations of 0.47 A for the backbone atoms in the secondary structure regions and 0.86 A for residues The side chains of Phe(23), Tyr(24), Tyr(25), Phe(35), and Phe(47) exhibited many long-range nuclear Overhauser effects and were the principal components of the hydrophobic core in BF9. To gain insight into the structure-function relationships among proteins in the BPTI-like superfamily, we compared the three-dimensional structure of BF9 with three BPTI-like proteins that possess distinct biological functions. These proteins possessed similar secondary structure elements, but the loop regions and beta-turn were different from one another. Based on residues at the functional site of each protein, we suggest that the flexibility, rigidity, and variations of the amino acid residues in both the loop and beta-turn regions are related to their biological functions.

Isolation and characterization of an active compound from black soybean [Glycine max (L.) Merr.] and its effect on proliferation and differentiation of human leukemic U937 cells

Black soybean [Glycine max (L.) Merr.] has been used as a health food and herb in China for hundreds of years. In the present study, we purified a unique polysaccharide component from black soybean (PSBS) and found that it indirectly inhibits proliferation and induces differentiation of human leukemic U937 cells via activation of mononuclear cells (MNCs). We prepared conditioned media (MNC-CM) by incubating MNCs from human peripheral blood with or without PSBS (PSBS-MNC-CM and normal MNC-CM, respectively). Treatment of human leukemic U937 cells with PSBS-MNC-CM significantly inhibited proliferation of U937 cells, reducing their growth by 98.5%. Furthermore, PSBS-MNC-CM induced U937 cells to differentiate into mature monocytes/macrophages (83% by morphological examination and 90% by the nitroblue tetrazolium test). Neither PSBS alone nor normal MNC-CM had such effects. The molecular weight of PSBS was about 480 000 by gel filtration. Structural analysis of PSBS revealed that (1,6)-alpha-D-glucan might be its major active component. Our results suggest that the PSBS may inhibit proliferation and induce differentiation in human leukemic U937 cells by activating the immune response of MNCs.

Multifunctionalized alpha,beta-cyclopentenones from C-2 and C-4-ulopyranosyl compounds: a stereospecific rearrangement initiated by base

Base treatment of O-benzyl protected C-2- or C-4-ulopyranosyl compounds (4 alpha, 4 beta, and 11) by either 10% Et(3)N or 1% K(2)CO(3) in MeOH initiated a beta elimination to afford alpha,beta-unsaturated C-ulopyranosyl compounds (5 alpha, 5 beta, and 12), which further rearranged in a stereocontrolled manner to multifuctionalized alpha,beta-cyclopentenones (6 and 14) in 70-80% yield. Both C-alpha- and C-beta-2-ulosides (5 alpha and 5 beta) produced the same cyclopentenone 6, indicating that a 1,2-enolate is formed prior to the cleavage of the C-5--O bond. Because 6 is racemic, it was probably formed by the intramolecular cycloaldolization of two equally populated enantiomeric intermediates. When treated with 90% Et(3)N in MeOH, 5 alpha yielded almost exclusively 15 (isomer of 6), which was formed by a migration of the double bond in 5 alpha during the previously described rearrangement. Thus either 6 or 15 was the major product, depending on the base used.

Sesquiterpenoids from Magnolia grandiflora

Three new sesquiterpenoids were obtained from the leaves of Magnolia grandiflora L. Their structures were determined as 6 alpha,11-dihydroxy-12,13-diacetoxyelem-1,3-diene, 4 alpha,6 alpha,10 alpha-trihydroxy-13-acetoxyguaia-11-ene, and 12,13-diacetoxyguaia-4 alpha,6 alpha,10 alpha,11-tetraol on the basis of spectral evidence. In addition, the known sesquiterpenoid magnograndiolide was also obtained.

Simultaneous analysis of enantiomeric composition of amino acids and N-acetyl-amino acids by enantioselective chromatography

Among the three chiral columns, CHIROBIOTIC T, CHIRLPAK WH, and CHIRALCEL OD-R, tested for the separation of racemic amino acids and N-acetyl-amino acids, only CHIROBIOTIC T chiral column which is based on covalently bonded amphoteric glycopeptide, teicoplanin, as the stationary phase ligand could be successfully developed to enantiomerically separate racemic amino acids and N-acetyl amino acids simultaneously. This method can be used to determine the enantiomeric composition of amino acids and N-acetyl-amino acids in the catalysis of D-aminoacylase or L-aminoacylase and the conversion rate of N-acylamino acid racemases.

ent-Pimarane derivatives from Dysoxylum hainanense

Four ent-pimarene diterpenoids. ent-18-acetoxy-8(14)-pimarene-15S, 16-diol, ent-18-acetoxy-16-hydroxy-8(14)-pimaren-15-one, ent-16,18-dihydroxy-8(14)-pimaren-15-one and ent-19-nor-4,16,18-trihydroxy-8(14)-pimaren-15-one, together with three known damarane triterpenoids, richenoic acid, eichleriainic acid and shoreic acid were isolated from the bark of Dysoxyhum hainanense Merr. Their structures were elucidated on the basis of spectroscopic techniques. The absolute configurations of four diterpenoids were assigned as ent-pimarene type by chemical transformation and by co-occurrence in the plant as well as by negative optical rotations for four compounds.

[Structural and functional study of prokaryotic enhancer-like element VV1 from vaccinia virus]

Enhancer VV1 (about 283 bp) is selected as the target to analyze its structure and function systemically. Stepwise deletion experiment is used to identify the functional domain of VV1 element. The results suggest that the 20 bp at 5' terminal and 20 bp at 3' terminal are important to the activity of VV1, for without either of them its activity decreased greatly. Furthermore, the 30-50 bp at 5' terminal is essential to its activity, without which will lead to complete loss of its activity. By random mutagenesis assay it is found that base mutation can regulate the activity of enhancer VV1 positively or negatively. The more the activities of mutants descend, the more mutations take place. For singlebase mutation, the activities change relatively little, and most of the mutations always occur in the 50 bp at the 5' terminal.

Morphology and physiology of neurons in the ventral nucleus of the lateral lemniscus in rat brain slices

The ventral nucleus of the lateral lemniscus (VNLL) is a prominent neuronal group that lies within the auditory pathway connecting the auditory lower brainstem and midbrain. Previous physiologic studies showed that VNLL neurons respond mainly to contralaterally presented sounds and display various firing patterns. To understand better the role that VNLL neurons play in transmitting and processing of auditory information, we examined the morphology of VNLL neurons and their cellular physiology in young rat brain slices. We made whole-cell patch-clamp recordings and labeled cells intracellularly with neurobiotin to investigate the relation between morphologic neuronal types, intrinsic membrane properties, and postsynaptic responses. VNLL neurons fell into two distinct morphologic groups, i.e., bushy cells and stellate cells, based on their dendritic patterns. Stellate cells were grouped further into stellate I, II, and elongate cells according to soma shape, dendritic branches, and orientation. Bushy cells showed an onset firing pattern and a nonlinear current-voltage relationship. All three subtypes of stellate cells had a linear current-voltage relationship, but exhibited different firing patterns. Stellate I cells showed regular and onset-pause firing patterns, whereas stellate II cells showed adapting and elongate cells showed burst firing patterns. Bushy cells and stellate cells responded to stimulation of the lateral lemniscus with excitatory and/or inhibitory synaptic potentials. These results suggest that the VNLL is a heterogeneous neuronal group and that it contains many channels for processing different kinds of auditory information. Neuronal morphology and intrinsic membrane properties contribute to the behavior of individual neurons.