Characterization of NMDA induced depression in rat hippocampus: involvement of AMPA and NMDA receptors.

• The involvement of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) vs. N-methyl-d-aspartate (NMDA) receptor mediated changes in NMDA-induced long-term depression (LTD) was assessed by monitoring isolated AMPA, isolated NMDA and composite field excitatory postsynaptic potentials (EPSP) in the CA1 area of acute rat hippocampal slices. Application of NMDA (20-50 microM) for 3-5 min led to LTD of both AMPA and NMDA receptor mediated EPSPs with near equal changes of the responses. However, AMPA EPSPs displayed a faster initial recovery than NMDA EPSPs. In addition, during the first 15-25 min after NMDA application, there was a superimposed potentiation of the later, but not early, part of AMPA EPSPs, implying a prolongation of waveform. In contrast, the NMDA EPSP waveform remained unaltered throughout the experiments. While it has been maintained that NMDA-induced depression is equivalent to stimulus-induced LTD, our results reveal additional complexity, suggesting a multitude of changes, most likely at the postsynaptic receptor level.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

Keyword

Animals

Excitatory Postsynaptic Potentials

drug effects

physiology

Long-Term Synaptic Depression

drug effects

physiology

N-Methylaspartate

pharmacology

Rats

Rats

Sprague-Dawley

Receptors

AMPA

agonists

physiology

Receptors

N-Methyl-D-Aspartate

agonists

physiology

Publication and Content Type

ref (subject category)

art (subject category)