Enriched Environment Modulates Sharp Wave-Ripple (SPW-R) Activity in Hippocampal Slices

Area of Science:

• Neuroscience
• Cognitive Science
• Neuroplasticity

Background:

• Behavioral flexibility relies on neuronal plasticity, shaped by environmental interactions.
• Enriched environments (EE) are known to induce cellular and behavioral changes, but their effect on network activity is less understood.

Purpose of the Study:

• To investigate the impact of EE exposure on spontaneous network activity in mouse hippocampal slices.
• To identify alterations in sharp wave-ripple complexes (SPW-R) associated with EE.

Main Methods:

• Electrophysiological recordings of hippocampal slices from mice exposed to EE for 10-15 days.
• Comparison of network activity patterns (SPW-R) between EE, standard condition (SC), and motor activity (MC) groups.

Main Results:

• EE exposure increased sharp wave amplitude, unit firing during sharp waves, and ripple cycle count.
• Spiking precision during ripple oscillations decreased in the EE group.
• Reduced synaptic inhibition and a lower inhibition-excitation ratio were observed in pyramidal cells during SPW-R.

Conclusions:

• EE exposure alters hippocampal network activity, specifically modifying SPW-R characteristics.
• Changes in synaptic inhibition efficacy, not neuron number, may underlie EE-induced network modifications.
• These network alterations likely contribute to the cognitive-behavioral benefits of enriched environments.