ASSOCIATIVE INFORMATION PROCESSING: CELLULAR MECHANISMS

  • Walters, Edgar T, (PI)

Project: Research projectResearch Project

Description

The objective of the proposed research is to identify cellular mechanisms
underlying associative learning and to relate these mechanisms to general
principles of information processing by sensory systems. Building on the
recent demonstration of activity-dependent associative plasticity in
individual sensory neurons mediating afferent input for the tail withdrawal
reflex in Aplysia, the proposed experiments will test the hypothesis that
this associative plasticity is a mechanism for classical conditioning of
tail withdrawal. Differential classical conditioning of tail withdrawal
will be examined in a semi-intact preparation in which behavioral and
cellular alterations in identified neurons within the reflex circuit can be
measured simultaneously. Alterations both in the monosynaptic connections
to identified tail motor neurons and in the electro-physiological
properties of the sensory neuron soma will be measured. Both classes of
assciative modification will be compared to associative plasticity produced
by pairing intracellular activation of sensory neurons with application of
the presumed reinforcing neuromodulator (serotonin) in both the semi-intact
preparation and the isolated sensory neuron soma. The possible
interactions of associatively specific activity-dependent neuromodulation
with changes in membrane potential and lateral inhibition will be examined
in an attempt to identify sensory processes that may contribute to more
complex features of associative learning such as sequence specificity,
overshadowing, and blocking. By precisely defining conditioning and test
stimuli in the semi-intact preparation and relating the effects of
conditioning with these stimuli to the details of cellular associations
measured under analogous conditions in the isolated soma, the groundwork
for an eventual quantitative model of associative processing in this
sensory system will be laid. Since learning is one of the fundamental
capabilities of most if not all nervous systems, these studies may shed
light on general mechanisms involved in both the normal function and some
of the dysfunctions of the human brain.
StatusFinished
Effective start/end date12/1/831/31/97

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health

Fingerprint

Automatic Data Processing
Nervous System
Sensory Receptor Cells
Learning
Aplysia
Head
Motor Neurons
Orthotic Devices
Gastropoda
Aptitude
Long-Term Memory
Wounds and Injuries
Interneurons
Regeneration
Carisoprodol
Tail
Classical Conditioning
Membrane Potentials
Neurotransmitter Agents
Reflex

Keywords

  • Medicine(all)