Neuroscience and Neurobiology Commons^™

Sensory Function And Gating Of Histaminergic Neuron C2 In Aplysia, Hillel J. Chiel

Faculty Scholarship

This paper explores the possible sensory function of the identified histaminergic neuron C2. Mechanical stimulation of a narrow region around the mouth of the animal (perioral zone) elicits brief depolarizing potentials in C2. Extracellular recordings from the peripheral axons of C2 indicate that the depolarizing potentials are due to action potentials that are conveyed from the periphery but do not invade the cell body, since they fail at a region with a low safety factor within the cerebral ganglion. These blocked axonal spikes (A- spikes) function as if they were excitatory synaptic inputs to C2, since the synaptic output of …

Activity Of An Identified Histaminergic Neuron, And Its Possible Role In Arousal Of Feeding Behavior In Semi-Intact Aplysia, Hillel J. Chiel

Faculty Scholarship

The possible functions of histaminergic neuron C2 were studied in an isolated head preparation from which it was possible to obtain intracellular recordings while the buccal mass exhibited feeding-like responses. Application of food to the lips of the isolated head preparation elicited rhythmic buccal movements that appeared to be ingestion responses, since they moved seaweed into the buccal cavity and towards the esophagus, and their frequency and regularity was similar to the ingestion responses studied in a group of intact animals. The ingestion responses of the buccal mass consisted of 2 main phases of movement of the radula from a …

An Identified Histaminergic Neuron Modulates Feeding Motor Circuitry In Aplysia, Hillel J. Chiel

Faculty Scholarship

An identified histaminergic neuron, C2, in the marine mollusk Aplysia is a complex mechanoafferent which appears to contribute to the maintenance of food arousal by means of its synaptic connections to the metacerebral cell (MCC). Because C2 also has extensive synaptic outputs to neurons other than the MCC, we studied its possible motor functions. We identified several synaptic followers of C2 and found that some were excitatory motor neurons for extrinsic muscles of the buccal mass, while others were modulatory motor neurons that inhibited contractions. In addition, we found that these neurons and other synaptic followers of C2 received powerful …

Patterns Of Fetal Lamb Regional Cerebral Blood Flow During And After Prolonged Hypoxia, Stephen Ashwal, John S. Majcher, Nestor Vain, Lawrence D. Longo

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract not included]

Speculation: In the fetal lamb during prolonged intrauterine hypoxia, total and regional cerebral blood flows increase to the same extent without evidence of preferential shunting to critical brainstem or subcortical areas. Neuropathologic studies have indicated relative sparing of these areas during similar animal experimental or human neonatal conditions. This suggests that the pattern of hypoxic ischemic insult to the neonatal central nervous system associated with asphyxia may differ from that produced by hypoxia alone. In addition, during asphyxia these pathologic changes may result primarily from hypotension and decreased regional cerebral blood flow, or from regional metabolic derangements …

Cerebral Anoxia And Its Residuals: Pt. Iii. The Structural Changes, Cyril B. Courville

Medical Arts and Sciences: A Scientific Journal of the College of Medical Evangelists

No abstract provided.