profound influence on motor functions. Brainstem Zona incerta receives input from many parts of the brainstem nuclei including the periaqueductal gray, raphe nuclei, thalamic reticular nucleus, and the deep layers of the superior colliculus. It is regulated by inputs from brainstem cholinergic nuclei such as the Laterodorsal tegmental nucleus and pedunculopontine nucleus upon its neuron’s muscarinic receptors. The rostral zona incerta also innervates the dorsolateral and ventrolateral compartments of the periaqueductal gray. Spinal cord Zona incerta afferents terminate within the spinal cord gray matter, particularly the anterior horn, while spinal projections back to the zona incerta arise from cells located across the posterior horn and intermediate gray. Other Zona incerta also has connections to the amygdala, basal forebrain, the osmoreceptors in the subfornical organ, olfactory bulb, posterior pituitary and habenula. Some of these projections appear in register; the representation of the same body part in cortex and spinal cord connect to the same areas in the zona incerta. This is possibly so with the superior colliculus. Function Visceral survival activities. Zona incerta controls such activities as water and food intake, sexuality and cardiovascular activity. This control is related to its effects upon the nearby posterior hypothalamus with which it shares similar connections and neurochemically defined cell types. Besides, activation of GABA neurons in rostral zona incerta evokes binge eating behavior with a preference to sweet and high-fat food. The inhibitory projection from zona incerta to paraventricular thalamus contributes to binge-like eating produced by zona incerta GABA neuron activation. Zona incerta has also been found to modulate both innate and learned defensive behaviors through its projections to the excitatory neurons of the dorsolateral and ventrolateral compartments of the periaqueductal gray. Activation of the GABAergic neurons in the rostral zona incerta reduces sound-induced innate flight response and conditioned freezing response. The zona incerta receives pain input through the spinothalamic tract and this has been shown to control the activity of the pain transmission pathway in the posterior thalamus. Electrical or chemical stimulation of the zona incerta creates limbic-related movements, such as those associated with defense orientation and copulation. Sensory-motor activities. At rest sensory input to the higher sensory areas of the cerebral cortex is gated through the thalamus. It has moreover been proposed that the zona incerta provides a top-down disinhibitory mechanism of this gating when there is sensory-motor activity such as the tactile use of whiskers. This has also been linked