Vaaga Lab

Survival requires animals to detect and appropriately respond to acute predator threats within the environment. To do this, animals express a variety of innate defensive behaviors that can be engaged in response to naturalistic stimuli mimicking predators, and importantly, do not require previous associative learning to be expressed. Such innate defensive behaviors, therefore, require dedicated neural circuits for threat detection, sensorimotor integration, and selection/execution of an ethologically appropriate defensive behavior.

The Vaaga lab is interested in elucidating the neural circuits that control innate fear behaviors, with a particular interest in understanding the contribution of the cerebellum to such behaviors. Our recent work has demonstrated that the neural circuits responsible for generating freezing are under modulatory control of the cerebellum. Therefore, cerebellar modulation of innate fear circuits may provide a synaptic substrate by which cerebellar-dependent associative learning alters innate fear pathways, providing increased circuit flexibility.

To address these questions, the lab employs an integrative approach, combining in vitro and in vivo electrophysiological approaches, circuit manipulation, and behavioral analysis to study the neural circuits responsible for generating innate defensive behaviors, with a particular interest in understanding the contribution of the cerebellum in modulating defensive circuits, and ultimately, behavior.

The Vaaga lab is currently full but always willing to consider highly motivated students. Those interested in undergraduate research or technician positions may reach out with their interest and contact information for two or three references. Graduate students may enter the lab through direct admission or rotations in the Molecular, Cellular and Integrative Neuroscience (MCIN) program. Interested postdocs may submit a CV, statement of research and interest, and contact information for two or three references.

research project

Role of the cerebellum in innate fear circuits

This project seeks to understand the nature of cerebellar activity during innate fear paradigms and examine how modulation of cerebellar circuits alters freezing behaviors.

research project

Microcircuitry of freezing-related circuits

This project aims to elucidate the microcircuitry and synaptic connectivity of local fear related circuits in the periaqueductal gray and understand how they respond to extrinsic inputs.

research project

Electrophysiological Development of cortico-nuclear synapse

This project is studying the electrophysiological development of the cerebellar cortico-nuclear synapse in both health and developmental disorders.


Simple spike patterns and synaptic mechanisms encoding sensory and motor signals in Purkinje cells and the cerebellar nuclei. Brown ST, Medina-Pizarro M, Holla M, Vaaga CE, Raman IM. Neuron. 2024. doi: 10.1016/j.neuron.2024.02.014.

Cerebellar Modulation of Synaptic Input to Freezing-Related Neurons in the Periaqueductal Gray. Vaaga CE, Brown ST, Raman IM. eLife. 2020. doi: 9:e54302.

more publications


Christopher Vaaga, Ph.D.

Principal Investigator
Assistant Professor

Kate McCabe

Research Associate II
Lab Manager

Portrait of Jordan Carroll
Jordan Carroll

PhD student

Raven McGann

MS student, Graduate Teaching Assistant
Biomedical Sciences

John Bouchard

MS student
Biomedical Sciences

Alex Norris

Undergraduate student

Bell Lopez

Undergraduate student
Biomedical Sciences

Madison Greves

Undergraduate student

contact information

Vaaga Lab
Department of Biomedical Sciences
Anatomy/Zoology, W204
Colorado State University
1617 Campus Delivery
Fort Collins, CO 80523