Auditory input to the pedunculopontine nucleus: I. Evoked potentials.
The pedunculopontine nucleus (PPN) has been implicated in sleep-wake control, arousal responses, and motor functions. The PPN also has been implicated in the generation of the P1 middle-latency auditory-evoked potential. The present study was undertaken to determine the topographical distribution, threshold, and response properties of depth-recorded potentials following auditory click stimulation. Experiments were conducted in both decerebrate cat and rat, with a view towards determining the presence of P1-like middle-latency auditory-evoked potentials in the midbrain of both species. These results demonstrate a) the presence in and around the PPN of a P1-like potential in the decerebrate rat similar to that described in the accompanying article as the P13 in the intact rat; b) the presence in and around the PPN of a P1-like potential in the decerebrate cat similar to that previously described by others as wave A in the intact cat; c) although thresholds for these potentials were similar to those of intact preparations, following frequencies were higher in the decerebrate preparations, i.e., responsiveness to repetitive stimulation was higher; and d) depth-recorded somatosensory-evoked potentials also were studied in the cat and found to show an evoked potential at a similar latency as middle-latency auditory depth-recorded potentials. These findings suggest that click stimulus-evoked, depth-recorded potentials are present in and around the PPN in the decerebrate rat and cat, i.e., in the absence of cortex, at a similar latency as in intact preparations.
Reese
N B
NB
Department of Physical Therapy, University of Central Arkansas, Conway 72035, USA.
Garcia-Rill
E
E
Skinner
R D
RD
D000161:Acoustic Stimulation; D000818:Animals; D002415:Cats; D003655:Decerebrate State / Q000503:physiopathology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D011149:Pons / Q000502:physiology*; D013239:Stereotyped Behavior / Q000502:physiology