Related Experiment Video
Updated: Mar 1, 2026
09:08
In Vivo Fiber-Coupled Pre-Clinical Confocal Laser-scanning Endomicroscopy pCLE of Hippocampal Capillaries in Awake Mice
Published on: April 21, 2023
1.3K
Abnormal neuronal responses during evolution of a penicillin epileptic focus in cat visual cortex
Journal of Neurophysiology
|March 1, 1975
Summary
Penicillin application in cat visual cortex causes neuronal hyperactivity, termed enhanced physiological response (EPR), and paroxysmal depolarization shifts (PDS). These changes, along with inhibition, reveal penicillin
Area of Science:
- Neuroscience
- Cortical plasticity
- Neuronal excitability
Background:
- Penicillin is known to induce epileptic activity in the brain.
- Understanding the specific neuronal alterations caused by penicillin is crucial for studying neuronal network dynamics.
Purpose of the Study:
- To investigate the progressive changes in neuronal activity in response to penicillin iontophoresis in the cat visual cortex.
- To differentiate between direct cellular effects and network-level phenomena induced by penicillin.
Main Methods:
- Single unit receptive fields in cortical area 17 of anesthetized cats were defined.
- Recurrent on-off stimulation with light bars was applied.
- Penicillin was iontophoresed to induce neuronal alterations.
Main Results:
- An early abnormality was an increase in spike number and frequency (enhanced physiological response, EPR).
- A later response, the extracellular paroxysmal depolarization shift (PDS), emerged, associated with ECoG interictal potentials and triggered by various stimuli.
- A period of response inhibition accompanied each interictal potential.
Conclusions:
- EPR is a direct effect of penicillin on cells or synapses.
- PDS depends on altered interactions within a population of affected cells.
- Inhibition results from influences of cells involved in the developing focus.
