Search PubMed⌕ Search

Biomedical subjects

D H Cohen

Publications and source records attributed to D H Cohen.

At least 55 records · Page 3Linked to original sources

The peripheral unconditioned stimulus pathway in a model learning system involving defensively conditioned heart rate change in the pigeon.

The peripheral pathway transmitting the unconditioned stimulus information is described in a vertebrate model system for studying learning-visually conditioned heart rate change in the pigeon. In this system footshock serves as the unconditioned stimulus, and it is shown that the effective stimulation field of this stimulus, defined with respect to the unconditioned cardioacceleratory response, includes cutaneous dermatomes 21-25 (L1-Sl). The stimulus information is then transmitted by Group III and IV fibers in portions of the femoral and sciatic nerves which enter the spinal cord over segments 21-25. Further, it is shown that interrupting this pathway by section of dorsal roots 21-25 precludes establishing conditioned heart rate change with footshock as the unconditioned stimulus.

Action Potentials↗

Electrophysiological identification of a visual area in shark telencephalon.

Optic nerve stimulation in the shark evokes short-latency telencephalic field potentials localized to the ipsilateral, posterior central nucleus. Such a well-defined visual area in elasmobranch telencephalon further challenges classical formulations of forebrain evolution. Moreover, its ipsilateral representation confirms recent evidence for a crossed thalamotelencephalic visual projection.

Animals↗