C.J. Sherry

Tongue manipulation of the palate assists estrous detection in the bovine.

To understand the mechanisms for introducing urine or vaginal secretions into the vomeronasal organ, we used 16 mm cinematography and a freeze frame/slow motion technique to analyze the mouth and tongue movements of Brahman bulls while they examined the vulvas of restrained, estrogen-primed cows. Prior to flehmen, the mouth slowly opened, the curled tip of the tongue compressed the hard palate and the body of the tongue protruded from the mouth. The tongue maintained this form and moved forward. Once the tip of the tongue reached the incisive papilla, the body of the tongue retracted and the tip of the tongue relaxed. This tongue compression stroke (TCS) of the hard palate occurred 2 to 6 times, lasting 1 4 to 1 2 sec/stroke. Pressure changes in the vomeronasal organ are assumed to occur during and following TCSs, resulting in aspiration of any liquid in the incisive pit into the incisive and vomeronasal ducts. Such aspiration probably does not occur during flehmen because the tongue is relaxed and on the floor of the mouth.

Structures of the bovine vomeronasal complex and its relationships to the palate: tongue manipulation.

The rostral part of the bovine vomeronasal complex was examined to determine its relation structures of the palate which are compressed by the tongue during investigative sexual behavior. The rostral vomeronasal cartilage (VNC) is C-shaped and contains the incisive duct (ID). The hilus of the cartilage is directed medially, approximately 0.5 cm dorsal to the palate. Just caudal to the origin of the vomeronasal duct, the VCN lies approximately 1 cm above the palate with a ventrally oriented hilus containing the ID. Further caudally, the hilus is directed laterally, toward the nasal cavity. Palatal mucosa occupies the intervomeronasal, cartilaginous area below the nasal septum and caudal to the incisive papilla. This mucosa and the ID appear to be compressed by the bulls everted tongue, forcing fluid samples into the vomeronasal system.

Homosexual behavior in feedlot steers: An aggression hypothesis

Abstract A common male homosexual vice in feedlot cattle is an activity where some steers, “bullers”, sexually attract other steers, “riders”. One theory of the cause is that bullers are excessively feminized and give off sexually stimulating pheromones. Because pheromones are detected in many mammals by the vomeronasal organ (VNO), we tested the role of this system by cauterizing duct openings which lead to the VNO. Cautery of non-bullers did statistically reduce bulling, but the magnitude of bulling was still high. Cautery of bullers revealed that they were indeed subjected to less mounting than were the non-cauterized bullers in the same herd. Bullers commonly participated in mounting and had aggression scores about twice that of riders. We believe that aggresssion is a key element in bulling behavior because: (1) most (over 80%) of the steers withdrew from the social contesting engaged in by both riders and bullers; (2) riders were challenged by bullers, in that bullers also mounted riders, as well as other bullers; (3) bullers were more aggressive than riders in the conventional measures of aggression; and (4) the amount of bulling was much greater during the periods of greatest social stress (such as just after the herds were formed and, in one pen, just after 50 new steers were added to the pen). Thus, we are led to advance a new hypothesis about bulling; namely, that it is a ritualized “game” based on social hierarchy contesting.

What is the meaningful measure of neuronal spike train activity

Neuronal spike train activity is conventionally viewed in terms of certain measures of central tendency (mean or median of intervals between discrete events or mean rate of such events) and their associated measures of variability (S.D., skew, etc.). Less commonly, investigators will compute the probabilities of occurrence in an Information Theory context. Another rarely considered measure of spike trains is serial ordering. Seldom is more than one of these approaches applied to the same spike train, and we are unaware of any case where all 3 have been applied to the same train. In order to test the inter-relationships among these approaches, we examined the same spike trains with all 3 analytic methods. Measures of central tendency were taken from the original absolute interval values, whereas entropy and serial order (Markov order) were computed from the sequences of patterns of adjacent intervals, expressed in the same non-parametric format. We found that entropy (measure of uncertainty) did not correlate well with the degree of serial ordering (Markov order). Entropy also did not correlate well with measures of central tendency (median or mean interval, or impulses/s) nor with the variability of such measures. An inverse correlation was seen between Markov order and several measures of central tendency (mean interval and rate) as well as with several measures of variability. The implications of these analyses extend beyond the analysis of spike trains to most all biological and physical time series. For neurophysiologists, these analyses may challenge our common assumptions about the most appropriate way to describe and interpret neuronal spike train activity.(ABSTRACT TRUNCATED AT 250 WORDS)

The statistical relationship between the "entropy" of a neuronal signal and its variability.

We used a serial order nonparametric analysis technique to analyze trains of neuronal action potential intervals in terms of classical information theory. We observed a marked correlation between the information theory descriptor, entropy, and several common measures of variability (median interval length, range of interval length, and skewness of the probability density function). The correlation between variability and entropy was accounted for in the following decreasing order: range of intervals, median interval, and skewness. These data suggest a significant relationship between the signal and its variability and entropy, when entropy is calculated by our serial-order pattern detection method.

An information coding system that seems to be independent of noise and variability

We have discovered and describe herein a cybernetic coding principle that appears to operate independently of variability. The coding is in the time domain, stated in terms of the relative duration of successive intervals between discrete events (pulses, action potentials, etc.). A variety of high-order relations can be described, quantified, and evaluated statistically.

EVIDENCE OF A ROLE FOR THE VOMERONASAL ORGAN IN SOCIAL HIERARCHY IN FEEDLOT CATTLE

Abstract This is study of the effects of obstructing the opening to the vomeronasal organ (VNO) on feed consumption, weight gain and social structure of 22 2-year-old Santa Gertrudis steers under experimental feedlot conditions. Obstructions were produced by either cautery or plugging of the duct that leads to the VNO. Feed intake and weight gain were similar in all 3 groups (control, cauterized and plugged) before, during and after the 4-week experiment. The pre-treatment social hierarchy, determined by conventional inter-individual aggression contests, was distinctly changed, and higher ranking pre-treatment steers generally lost rank and lower ranking steers gained rank. Treated steers (plugged and cauterized) often gained rank over controls. Thus, we are led to postulate that the VNO has a role in the aggressive behaviors that contribute to social hierarchy in the bovine.

Entropy correlations with ethanol — Induced changes in specified patterns of nerve impulses: Evidence for ‘byte’ processing in the nervous system

Abstract 1. 1. Average entropy, percent total entropy, and the variability of entropy (standard deviation, coefficient of variation) were calculated on the basis of inequality test techniques that encode the serial relationships of 2–5 neuronal action potential intervals as a series of symbols. 2. 2. These entropy measures correlated with the number of patterns (symbol groups) whose probability of occurrence changed in a statistically significant manner in response to ethanol injections. 3. 3. The overall ‘message,’ or at least the change in the ‘message’ induced by ethanol injections, seems to have been encoded by the relative changes in the probability of occurrence of certain quadgrams (i.e. a grouping of four symbols based on the serial order relationship of five intervals). The ethanol induced ‘message’ may be based on the combination of certain quadgrams that increase in incidence and those that decrease in incidence (i.e. the quadgrams whose incidence changes in opposite directions, may be ‘linked’ in some way). This suggests some higher order pattern analysis or ‘byte’ processing by neurons in the central nervous system.

Serial-order analysis of spike trains: Ethanol effects on cerebellar neurons, with and without penicillamine

Abstract 1. 1. We used a powerful serial-order analysis technique to test the hypothesis that some of ethanols intoxicating effects could be due to action of its metabolite, acetaldehyde. 2. 2. Single-unit activity from cerebellar cortex was evaluated in 24 rats that were given ethanol intravenously (0.64 gm/kg); in half of these rats, acetaldehyde accumulation was prevented by pretreatment with d-penicillamine (1.2 mg/kg), which is known to prevent acetaldehyde accumulation as ethanol is metabolized. 3. 3. Spike train interval patterns were monitored before and after ethanol, and the incidence of certain patterns was significantly changed in both test groups by ethanol. Across neurons, the number of such patterns in which there were increases or decreases in incidence was comparable in both pretreatment groups. Likewise, there were no clear differences between test groups in the number of sets of 3 or more neurons that had the same change in specific groups of patterns. 4. 4. Overall, we found that the serial-order analysis provided a powerful and sensitive indication of drug effect, yet there was no convincing evidence that ethanol effect was significantly different in the two pretreatment groups.

Innervation of the feline eyelids

The innervation of the eyelids is incompletely understood. This is a particular problem for those who wish to develop animal models of eyelid dysfunction in humans. Blepharospasm, for example, is a disease of uncontrolled eyelid spasm that is difficult to manage clinically because the aetiology is not understood. The anatomical literature on eyelid innervation is sparse and even conflicting. We attempted to study eyelid innervation, both sensory and motor, with injection of horseradish peroxidase (HRP) into the superior eyelid, inferior eyelid, and bulbar conjunctiva. We used 13 anesthetized weanling cats. Shape and structure of the facial nucleus varied along its rostrocaudal extent, but there was a clear demarcation of lateral and medial division. HRP-filled facial nucleus cells were ipsilateral to the injection site, and label appeared throughout the rostrocaudal length. All injection sites, including bulbar conjunctiva, labelled facial nucleus neurons located with overlapping distribution, predominantly in the dorsal part of the lateral division. Likewise, heavy labelling occurred throughout the entire ipsilateral cranial cervical ganglion and the trigeminal ganglion in all kittens. Injection of upper or lower eyelids caused some labelling in the second through the fourth cervical spinal ganglia.