Characterization of Thermosensitive Preoptic Neurons in the Green Sunfish, Lepomis Cyanellus

(1) The local thermosensitivities of 276 neurons in the preoptic region of green sunfish acclimated to 25(DEGREES)C were obtained using extracellular recording techniques and classified into 5 basic types. Type 1 neurons, which comprised 4% of the total, had low firing rates (approximately 5/second) at 25(DEGREES)C brain temperature. Firing rate increased exponentially with increasing brain temperature and remained constant at brain temperatures below 25(DEGREES)C. Type 1 neurons discharged in a continuous, rhythmic manner with a constant interspike interval at a constant brain temperature. Type 2 neurons comprised 2% of the total and were cold sensitive and increased their firing rate with decreasing brain temperature. These cells discharged in a continuous sporadic manner and possessed of mean firing rate of 10/second at 25(DEGREES)C. Type 3 neurons (5% of total) discharged in a continuous nonrhythmic manner and displayed linear increases in firing rate with increasing brain temperatures. They were characterized by higher spontaneous firing rates. Type 4 neurons were insensitive to local brain temperature changes and comprised the majority of the cells (81%). Type 5 neurons were characterized by a high spontaneous discharge rate and discharged in a continuous sporadic manner. They comprised 8% of the total. Type 5 response curves showed regions of low thermosensitivity which changed to high or insensitivity with increasing brain temperature.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Nelson, Douglas Olie

• Biology, Animal Physiology

Language dc:language

eng

Identifier

(UMI)AAI8108613

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/68307