because of continuous changing of anatomy, function and metabolism of the human brain, age- related change is a major risk factor in most prevalent neurodegenerative diseases, including parkinsons and huntingtons disease. therefore, knowing patterns of age-related atrophy of brain tissue can identify causes and possible role of diseases in decreasing brain function with age. the aim of this stu...

Amnesic patients and nondemented patients with Parkinson's disease were given a probabilistic classification task in which they learned which of two outcomes would occur on each trial, given the particular combination of cues that appeared. Amnesic patients exhibited normal learning of the task but had severely impaired declarative memory for the training episode. In contrast, patients with Par...

A local infusion of d-amphetamine (d-AMPH) into the dorsal raphe nucleus (DRN) inhibited neuronal activity in this site and produced a mirror-image excitation in the ventrolateral, but not dorsomedial, neostriatum. This effect, which was mimicked by 5-methoxy-N,N-dimethyltryptamine, a serotonin autoreceptor agonist, was not altered by pretreatment with alpha-methyl-p-tyrosine. Similar regional ...

A subpopulation of neurons in the globus pallidus projects to the neostriatum, which is the major recipient of afferent information to the basal ganglia. Given the moderate nature of this projection, we hypothesized that the pallidostriatal projection might exert indirect but powerful control over principal neuron activity by targeting interneurons, which comprise only a small percentage of neo...

The neostriatum controls behavioral sequencing, or action syntax, as well as simpler aspects of movement. Yet the precise nature of the neostriatums role in sequencing remains unclear. Here we used a "natural action" approach that combined electrophysiological and neuroethological techniques. We identified neostriatal neurons that code the serial order of natural movement sequences of rats. Dur...

Glutamatergic neurotransmission in the neostriatum and the globus pallidus is mediated through NMDA-type as well as other glutamate receptors and is critical in the expression of basal ganglia function. In order to characterize the cellular, subcellular and subsynaptic localization of NMDA receptors in the neostriatum and globus pallidus, multiple immunocytochemical techniques were applied usin...

Microinjection studies have found that although dynorphin peptides decrease dopamine release in the rat basal ganglia, the nonselective opiate antagonist naloxone produces the opposite effect. To investigate the contribution of the dynorphin pathways to a tonic modulation of dopamine release, a microdialysis study was undertaken, with probes implanted in the substantia nigra and the ipsilateral...

This study used the peptides omega-conotoxin GVIA, omega-agatoxin IVA and omega-conotoxin MVIIC, singly and in combination, to investigate the relative involvement of N-, P- and Q-type voltage-operated calcium channels in the control of striatal dopamine release. Electrically stimulated dopamine release was measured by fast cyclic voltammetry at carbon fibre microelectrodes in rat striatal slic...

Dopamine is a neuromodulator the functions of which in the regulation of complex behaviors such as mood, motivation, and attention are well known. Dopamine appears in the brain early in the embryonic period when none of those behaviors is robust, raising the possibility that dopamine may influence brain development. The effects of dopamine on specific developmental processes such as neurogenesi...