title: Distinct response properties of rat prepositus hypoglossi nucleus neurons classified on the basis of firing patterns.
abstract: Neurons in the prepositus hypoglossi nucleus (PHN), which is involved in controlling horizontal gaze, show distinct firing patterns in response to depolarizing current pulses. Although the firing patterns are commonly used to classify neuron types, whether the classified PHN neurons show differences in voltage response properties when stimulated with various types of current inputs remains unclear. In this study, we investigated the response properties of PHN neurons to various current stimuli using whole-cell recordings in rat brainstem slices. In response to pulse currents, neurons that exhibited oscillatory firing (OSC type) showed greater gain than other types, and neurons with a low firing rate (LFR type) showed strong overshooting firing responses to ramp currents. In response to triangular ramp currents, the late-spiking type and the LFR type showed a marked hysteretic frequency-current relationship. In response to sinusoidal currents, the gain was larger in the OSC type than in the other types, although the gain and phase of all types of neurons were similarly modulated by an increase in the input frequency. These findings suggest that distinct neuron types show distinct response properties, depending on the type of stimulus. These neuron types may represent the functionally different populations in the PHN.
authors.affiliation: Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan; Department of Neurophysiology, Nara Medical University, Kashihara, Nara 634-8521, Japan. Electronic address: syasu@naramed-u.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan.
authors.forename: Yuchio
authors.initials: Y
authors.lastname: Yanagawa
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001703:Biophysics; D001933:Brain Stem / Q000166:cytology*; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000145:classification* / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats
keywords: Frequency response; Hysteresis; Neural integrator; Transient response; Whole-cell recording