Neuroscience and Behavioral Physiology

, Volume 14, Issue 3, pp 211–217 | Cite as

Neuronal activity of the hippocampus deprived of ascending brain stem influences

  • E. S. Brazhnik
  • O. V. Vinogradova
Article
Received:

Conclusions

  1. 1.

    After basal undercutting of the septum the hippocampus is deprived of ascending direct influences of the brain stem structures and those redirected to the septum, and in a third of the neurons of fields CA1 and CA3 low-frequency (3.3–4.5 Hz) rhythmic bursts can be observed. Theta-like vibrations with a similar low frequency are recorded on the EEG of the hippocampus. Intravenous introduction of eserine leads to a limited increase in the frequency of the rhythmic component (within a range of 1 Hz).

     
  2. 2.

    The neurons are characterized by a low (46–47%) reactivity to sensory stimuli.

     
  3. 3.

    The nature of the specific and phasic reactions, typical under normal conditions for field CA1, does not change but they can be observed in both fields. There appear unusual prolonged effects expressed in a stable shift of the level of the activity of the neurons during the period of application of a series of sensory stimuli, and also slowly developing diffuse activation reactions that increase indefinitely in duration. The normal extinction of the reactions is impaired, in the majority of cases the dynamics being incremental in nature.

     
  4. 4.

    One can observe a sudden fall in the number of tonic inhibiting effects.

     

Keywords

Neuronal Activity Brain Stem Phasic Reaction Activation Reaction Sensory Stimulus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Plenum Publishing Corporation 1984

Authors and Affiliations

  • E. S. Brazhnik
    • 1
  • O. V. Vinogradova
    • 1
  1. 1.Institute of Biological PhysicsAcademy of Sciences of the USSRPushchino

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