Thalamic reticular nucleus activation reflects attentional gating during classical conditioning

All senses, except olfaction, are routed through the thalamus to cerebral cortex. Thus, the thalamus is often referred to as the sensory gateway to cortex. Located between thalamus and cortex is a thin lamina of neurons called the thalamic reticular nucleus, which may function as an attentional gate. The phenomenon of blocking in classical conditioning provides an opportunity to test whether an attended stimulus activates the thalamic reticular nucleus more than an unattended stimulus: when a second stimulus is presented together with a previously conditioned stimulus, conditioned responding to the second stimulus is inhibited. Different groups of rats were given conditioning sessions with a single stimulus, a light or a tone, and then given conditioning sessions with compound (light and tone) stimuli. Blocking was confirmed using probe trials of single stimulus presentations

Optogenetic Inactivation Modifies Monkey Visuomotor Behavior

A critical technique for understanding how neuronal activity contributes to behavior is determining whether perturbing it changes behavior. The advent of optogenetic techniques allows the immediately reversible alteration of neuronal activity in contrast to chemical approaches lasting minutes to hours. Modification of behavior using optogenetics has had substantial success in rodents but has not been as successful in monkeys. Here, we show how optogenetic inactivation of superior colliculus neurons in awake monkeys leads to clear and repeatable behavioral deficits in the metrics of saccadic eye movements. We used our observations to evaluate principles governing the use of optogenetic techniques in the study of the neuronal bases of behavior in monkeys, particularly how experimental design must address relevant parameters, such as the application of light to subcortical structures, the spread of viral injections, and the extent of neuronal inactivation with light

Optogenetic inactivation modifies monkey visuomotor behavior. Neuron

SUMMARY A critical technique for understanding how neuronal activity contributes to behavior is determining whether perturbing it changes behavior. The advent of optogenetic techniques allows the immediately reversible alteration of neuronal activity in contrast to chemical approaches lasting minutes to hours. Modification of behavior using optogenetics has had substantial success in rodents but has not been as successful in monkeys. Here, we show how optogenetic inactivation of superior colliculus neurons in awake monkeys leads to clear and repeatable behavioral deficits in the metrics of saccadic eye movements. We used our observations to evaluate principles governing the use of optogenetic techniques in the study of the neuronal bases of behavior in monkeys, particularly how experimental design must address relevant parameters, such as the application of light to subcortical structures, the spread of viral injections, and the extent of neuronal inactivation with light