Amphetamine alters evoked responses of nigral neurons in kittens and adult cats
Autor: | Robin S. Fisher, C.D. Hull, Michael Levine, N.A. Buchwald |
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Rok vydání: | 1982 |
Předmět: |
Aging
Nigrostriatal pathway Substantia nigra Stimulation Dopamine medicine Premovement neuronal activity Animals Amphetamine Molecular Biology Evoked Potentials Neurons Afferent Pathways CATS Chemistry General Neuroscience Substantia Nigra medicine.anatomical_structure nervous system Excitatory postsynaptic potential Cats Neurology (clinical) Neuroscience Developmental Biology medicine.drug |
Zdroj: | Brain research. 237(2) |
ISSN: | 0006-8993 |
Popis: | The effects of i.p. amphetamine administration (5 mg/kg) on the evoked unitary responses of substantia nigra (SN) neurons to electrical stimulation of their afferents were tested in 4 kittens (3-27 days of age) and 4 adult cats. In adults, amphetamine had two major effects: (1) it blocked temporarily (15-30 min) all neuronal responses caudate (Cd) and cortical (Cx) stimulation; neuronal responsiveness recovered by 75 min post-drug; and (2) after 15 min postdrug, Cd and Cx stimulation evoked initial excitatory responses that were almost never found predrug. The latencies of Cd-evoked excitations indicated the existence of a mono- or oligosynaptic excitatory strionigral pathway while latencies of Cx-evoked excitations suggested that corticonigral excitatory influences were mediated multisynaptically. In kittens, amphetamine also produced an initial blockade of Cd- and Cx-evoked responses. However, the sign of initial responses to Cd stimulation was not altered since excitations were found both before and after drug treatment. These results indicated that amphetamine reveals excitatory evoked responses of SN neurons to striatal and striatally-mediated inputs that are masked during the course of normal postnatal development. Drug-related alterations of afferent inputs to SN neurons may underlie amphetamine-induced shifts in spontaneous neuronal activity which have been reported frequently. |
Databáze: | OpenAIRE |
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