Oscillations in the Striatum in Mice and Their Relationship with Behavioral Events

In this thesis work, we investigate oscillations in the field potential recorded in the striatum and cortex of freely moving mice. Neurophysiological recordings of the striatum are conducted using a device consisting of 4 tetrodes attached to a micromanipulator that allows for varying their position once the laboratory-developed implant is in place. A correlation is observed between behavioral phenomena (initiation and termination of locomotor movement) and an increase in amplitude in the beta frequency band (15 - 30 Hz) of the field potential. A method is developed to detect events of activity in this frequency band and characterize them. The duration of the events is on the order of ∼240 ms in both structures. Two populations of events are identified when classified by their frequency, centered around ∼18 and ∼24 Hz in both the cortex and striatum. Additionally, the presence of gamma band activity is observed during beta activity events. The phase of the latter modulates the former, indicating an interaction and leaving open the possibility that they are part of the same circuit. It is also observed that the events occur simultaneously in both structures. These results contribute to understanding the circuit's functioning and how changes in it are related to different pathologies involving the basal ganglia, such as Parkinson's disease.