| Summary: | 碩士 === 國立政治大學 === 心理學系 === 84 === Catecholamine (CA) neurotransmission systems are critically
involved in the control of many behavioral functions including
learning and memory. The role of CA in mediating learning and
memory is recently focused on the basis of multiple memory
hypothesis. In addition to the previous finding of spatial
memory relevant to the hippocampal areas, the striatum
containing the caudate nucleus and the nucleus of accumbens is
thought to be important for executing the learning and memory
function. By the use of radial arm maze (RAM), the present
study examined the effects of CA related neurotoxins and drugs
on the acquisition and retention stages of both place and
response tasks. Two major parts of experiments were designed to
reveal the neurobehavioral mechanisms for the place and response
tasks of RAM. Food-deprivated rats were trained to enter the
arms baited with chocolate in the eight-arm maze. Specific four
arms were baited for each rat in the place task, while randomly
selected four arms each cued with a piece of sand paper on the
arm entrance were baited for the rat in the response task.The
results can be summarized as followings. (1) Differen
behavioral processes were shown in performing the place and
response tasks. (2) The acquisition deficits were significantly
produced by 6-hydroxydopamine (6-OHDA) lesion on either caudate
or accumbens for the place task, whereas the acquisition of
response task was only impaired by 6-OHDA lesions of both
caudate and accumbens together. (3) In contrast to 6-OHDA,
adrenergic neurotoxin DSP-4 did not significantly affect
subjects to acquire either task. (4) During the retention
stage, the performance of place task was significantly disrupted
by d-amphetamine, haloperidol, or propranolol. However, this
was not the case for the retrieval of response task. (5) Once
acquired, neither place nor response task performamce could be
influenced by 6-OHDA simultaneously administered on the caudate
and accumbens areas.Taken together, these data collected from
RAM support the idea that the striatal CA is essential for the
leraning and memory. Shift of the CA neurotransmission function
induced by either 6-OHDA lesions or relevant drugs can disrupt
the RAM behavior, which impairment to be detectable is depended
on the learning task itself as well as the time of a specific
task being leraned.
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