NEURAL SYSTEMS OF INGESTIVE BEHAVIOR

Project: Research project

Description

Energy, water, and electrolyte balance are among the most closely
regulated parameters found in vertebrates. Even minor, uncorrected
defects in any one system can become life threatening, and obligate
loss occurs continuously. Most of the processes involved in these
systems regulate physiological parameters and conservation. Only
one process, ingestion of foods or fluids, can replenish supplies
of nutrients, electrolytes, and water. The goal of the research
outlined in this proposal is to understand the neural mechanisms
that govern the decision to ingest or reject the contents of the
oral cavity. Evidence from this and other laboratories indicates
that the substrates for this neural decision are complete in the
brainstem -- the midbrain, pons, and medulla. Sensory information
from the oral cavity -- tactile, thermal, and gustatory afferent
activity -- first reaches the brain in the pons and medulla. Vagal
visceral afferent activity can switch the response elicited by oral
stimuli from one of ingestion to one of rejection. The vagus nerve
also synapses in the medulla. Finally, the motor neurons that
produce ingestive behavior are located in the medulla and pons, and
the interneurons that project to these oral motor nuclei form a
continuous distribution in the medullary and pontine reticular
formation. Chronic precollicular decerebrate preparations exhibit
normal ingestion and rejection behavior and, given an appropriate
visceral stimulus, will switch their response from ingestion to
rejection. Using neuroanatomical, electrophysiological, and
behavioral analysis, this project will examine the anatomical and
physiological relationships among the nucleus of the solitary tract
(NST) and the parabrachial nuclei (PBN), the first two sensory
relays for oral and visceral afferent activity, as well as the
parvicellular reticular formation (PRF). Specific experiments will
examine (1) the axonal connections among functionally defined
subdivision of NST and PBN and the oral motor interneurons in PRF,
(2) the responses of single neurons in NST, PBN, and the
parvicellular reticular formation to both oral and visceral
stimuli, and (3) the behavioral capacity of preparations with
either lesions or axonal disconnections of the solitary or
parabrachial nuclei. In addition to contributing toward the basic
understanding of how the nervous system coordinates diverse sensory
information into precise physiological and behavioral controls,
this research has direct relevance to the sensory mechanisms
involved in the etiology of a variety of morbid conditions.
Specifically, excess ingestion of carbohydrates, fats, and sodium
is highly correlated with, and may the causally related to obesity,
diabetes, and hypertension.
StatusFinished
Effective start/end date3/1/883/31/16

Funding

  • National Institutes of Health: $220,085.00
  • National Institutes of Health: $319,041.00
  • National Institutes of Health: $406,095.00
  • National Institutes of Health: $168,022.00
  • National Institutes of Health: $319,041.00
  • National Institutes of Health: $216,108.00
  • National Institutes of Health: $261,203.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $319,041.00
  • National Institutes of Health: $305,599.00
  • National Institutes of Health
  • National Institutes of Health: $418,280.00
  • National Institutes of Health: $394,267.00
  • National Institutes of Health
  • National Institutes of Health: $90,749.00
  • National Institutes of Health
  • National Institutes of Health: $314,726.00
  • National Institutes of Health
  • National Institutes of Health: $329,588.00
  • National Institutes of Health: $301,626.00
  • National Institutes of Health: $347,143.00
  • National Institutes of Health
  • National Institutes of Health: $303,089.00
  • National Institutes of Health
  • National Institutes of Health: $322,300.00
  • National Institutes of Health: $301,626.00

Fingerprint

Eating
Solitary Nucleus
Brain Stem
Pons
Prosencephalon
Reward
Obesity
Reticular Formation
Motor Neurons
Interneurons
Visceral Afferents
Touch
Brain
Food
Pleasure
Mouth
Hot Temperature
Feeding Behavior
Behavioral Research
Hypertension