Related Experiment Videos
Frequency-response characteristics provide a functional separation between stimulation-bound feeding and
1Department of Psychology, University of Pennsylvania, Philadelphia 19104.
Physiology & Behavior
|May 1, 1990
Summary
This study reveals that brain stimulation for self-reward and feeding behaviors, though possibly using common neural pathways, integrate signals differently. This suggests distinct neural processing for reward and hunger.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
- Neurobiology
Background:
- Electrical stimulation of the lateral hypothalamus can elicit both self-stimulation (reward) and feeding behaviors.
- Axonal properties (refractory period, conduction velocity) suggest a common neural substrate for these behaviors.
- It remains unclear how neural activity is integrated within this substrate to control each behavior.
Purpose of the Study:
- To investigate the neural integration mechanisms underlying self-stimulation and stimulation-bound feeding.
- To compare how different current intensities and frequencies of brain stimulation affect these two behaviors.
- To determine if the neural substrates for reward and feeding integrate neural activity similarly.
Main Methods:
- Generation of rate-frequency curves for self-stimulation (measured by bar press rate) and stimulation-bound feeding (measured by ingestion rate).
- Systematic variation of electrical current intensities delivered to lateral hypothalamic electrodes.
- Analysis of how changes in current intensity alter the rate-frequency relationships for each behavior.
Main Results:
- For self-stimulation, increasing current intensity shifted rate-frequency curves to lower frequencies, consistent with established findings.
- For stimulation-bound feeding, increasing current intensity primarily elevated the asymptotic ingestion rate, with less consistent shifts in frequency response.
- The parametric profiles of rate-frequency curves differed significantly between self-stimulation and stimulation-bound feeding.
Conclusions:
- The distinct parametric profiles suggest that the neural substrates controlling self-stimulation and stimulation-bound feeding integrate neural activity differently.
- These findings indicate separate neural processing mechanisms for reward and consummatory behaviors within the lateral hypothalamus.
- Further research is needed to elucidate the specific neural circuits and integration processes involved.