Life Sciences Commons^™

The Role Of Gaba In Reproductive Neuroendocrine Systems, Robert Carter Mcree

Theses and Dissertations in Biomedical Sciences

Local gamma-amino butyric acid (GABA) neurons in the hypothalamus can modulate the luteinizing hormone releasing hormone (LHRH) pulse generating system.

Two animal models (intact and ovariectomized rats) were used to determine the nature of modulation of LHRH release by GABA. The experiment determined the release of LHRH, serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) during two hormonal states with each model. In the intact rat the proestrus and estrus states were examined, and in the ovariectomized rat in-vitro release was determined with (OVX₂) and without (OVX) estradiol treatment.

In-vivo experiments studied the effect of stimulation of GABA receptors …

Action Of Heptaminol Hydrochloride On Contractile Properties In Frog Isolated Twitch Muscle Fibre, Bruno Allard, Vincent Jacquemont, Fouad Lemtiri-Chlieh, Bernard Pourrias, Oger Rougier

fouad Lemtiri-Chlieh

1 Heptaminol stopped or delayed the progressive decline in tension which characterizes the phenomenon of fatigue in frog isolated twitch muscle fibre. 2 Heptaminol had no action on the sodium, potassium and calcium voltage-dependent ionic conductances. 3 The hypothesis of an action via an internal alkalinization was tested by comparison with the action of NH4Cl. Both substances increased the tension. 4 The action of hepataminol was suppressed in sodium-free (TRIS) solution or in the presence of amiloride while the action of NH4Cl was always observed. 5 These results could be explained by a stimulation of the Na/H antiport by heptaminol.

Postsynaptic Modulation Of Rectifying Electrical Synaptic Inputs To The Lg Escape Command Neuron In Crayfish, Donald H. Edwards, William J. Heitler, Esther M. Leise, Russell A. Fricke

Neuroscience Institute Faculty Publications

The lateral giant (LG) tail-flip escape system of crayfish is organized to provide a massive convergence of mechanosensory inputs onto the LG command neuron through electrical synapses from both mechanosensory afferents and interneurons. We used electrophysiological techniques to show that the connections between three major mechanosensory interneurons and LG rectify, and that their inputs to LG can be reduced by postsynaptic depolarization and increased by postsynaptic hyperpolarization. The mechanosensory afferents and interneurons are excited by sensory nerve shock, and the components of the resulting LG PSP can be similarly modulated by the same postsynaptic potential changes. Because these inputs are …

Effect Of Age On The Structure Of Meissner Corpuscles In Forepad Digital Pads Of Mice, Roger C. Mathewson

Loma Linda University Electronic Theses, Dissertations & Projects

Meissner corpuscles in forepaw digital pads of albino mice were examined by light and electron microscopy to determine structural age-changes. After 1.5 months of age, no intraepidermal nerve fibers were seen extending from corpuscles. From young (1.5-6 months) to middle age (9-15 months), corpuscles became larger and more complex, gaining more horizontally arranged terminals, associated lamellae and connective tissue. At old age (18-26 months), corpuscles became small and lobulated, appearing disorganized. There was no loosening of the corpuscle-epidermal interface. An increase in collagenous connective tissue and basal lamina duplication occurred with advancing age. Ultrastructural age-changes consisted of disorganization of the …

Mutual Inhibition Among Neural Command Systems As A Possible Mechanism For Behavioral Choice In Crayfish, Donald H. Edwards

Neuroscience Institute Faculty Publications

Mutual inhibition among behavioral command systems frequently has been suggested as a possible mechanism for switching between incompatible behaviors. Several neural circuits in crayfish that mediate incompatible behaviors have been found to interact through inhibition; this accounts for increased stimulus threshold of one behavior (e.g., escape tailflip) during performance of others (eating, walking, defense). To determine whether mutual inhibition between command systems can provide a mechanism that produces adaptive behavior, I developed a model crayfish that uses this mechanism to govern its behavioral choices in a simulated world that contains a predator, a shelter, and a food source. The crayfish …

The Palmer Philosophy Of Chiropractic – An Historical Perspective., Dennis M. Richards

Dennis M Richards

This paper presents the Palmer philosophy of chiropractic from an historical viewpoint. It examines how influences in the life of DD Palmer, such as spiritualism, theosophy and magnetic healing helped to shape the chiropractic philosophy expressed by him. It also oulines the philosophy of BJ Palmer, explaining how it may have been influenced by legal challenges to the early pioneers of chiropractic. Contemporary expression of the Palmer philosophy, as articulated by Strang, is also noted.

Ortho-Aminoacetophenone Repellency To Birds: Similiarities To Methyl Antrhanilate, Russell Mason, Larry Clark, Pankaj Shah

Larry Clark

Methyl anthranilate is an effective bird repellent at concentrations 2:1.0% (g/g). Ortho-ami­ noacetophenone (OAP) has an odor similar to that of methyl anthranilate and is chemically (structurally) similar. Coincidentally, OAP is present in the scent gland secretions of mustelid species that prey on birds. For these reasons, we chose to test the bird repellency of this material and 3 isomers to European starlings (Stumus vulgaris). Ortho-aminoacetophenone was repellent at concentrations :50.01% in both choice and no-choice feeding tests. The other structural isomers (meta-, para-, alpha-) were less effective. Chemically, the results suggest that hydrogen-bonded ring structure formation and basicity predict …

Nonlethal Bird Repellents: In Search Of A General Model Relating Repellency And Chemical Structure, Larry Clark, Pankaj Shah

Larry Clark

Identification of potential repellents through molecular modeling has implications for the devel­ opment of commerciaUy viable, ecologically sound. nonlethal bird repellents. We tested isomers (ortho, meta, para) and moieties (amino, hydroxy, methoxy) of acetophenones for their effectiveness as bird repellents to better understand the nature of repellency in birds. ChemicaUy, basicity of a substituted phenyl ring, as de&ned by the electron-donating substituent, probably is an important feature infiuencing repellency; i.e., more basic substituents result in more potent repellents. Isomeric position of the electron-donating substituent, which leads to resonance of lone pairs of electrons.• is also an important feature of repellency; …

Chemical Bird Repellents: Applicability For Deterring Use Of Waste Water, Larry Clark, Pankaj Shah

Larry Clark

Regulatory agencies have placed increasing emphasis on agriculture and industry to protect wildlife from mortality associated with the consumption of waste water. Traditional hazjng methods to keep birds away from areas have met with marginal success. The only effective commercially available solution is .to enclose impoundments with netting. This strategy is costly and is subject to engineering constraints when large areas are to be protected. Molecular modeling techniques were used to identify chemical repellents to be added to waste water. These repellents effectively prevent birds from drinking or swimming in treated water.The most effective repellents are those containing an electron …

Prediction Of Avian Repellency From Chemical Structure: The Aversiveness Of Vanillin, Vanillyl Alcohol, And Veratryl Alcohol, Pankaj Shah, Larry Clark, Russel Mason

Larry Clark

The effectiveness of bird repellents is associated with the presence of an electron-withdrawing group (carbonyl or carboxyl) and an electron-donating group in resonance on a phenyl ring. The present experiments were designed to examine the relative importance of these structural features. European starlings (Sturnus vulgaris) were presented with vanillin, vanillyl alcohol, and veratryl alcohol in two-cup and one-cup feeding trials and in one-bottle drinking tests. In feeding trials, veratryl alcohol was significantly more aversive than the other two chemicals. In drinking tests. veratryl alcohol was repellent only at the highest concentration (0.5% ml/ml), and was lethal at that concentration and …

Physiological Responding In Anhedonic And Perceptually Aberrant College Students, Kathryn Elizabeth Stauffer

Dissertations, Theses, and Masters Projects

No abstract provided.