Brain histamine depletion enhances motor sequences complexity of mice tested in open field: new insights from temporal pattern analysis

Background: Tourette Syndrome (TS) has been classically related to dopaminergic dysregulation of Basal Ganglia circuitry [1]. However, the identification of a rare autosomal dominant form of TS, linked to a mutation of the key-enzyme for Histamine (HA)1 synthesis (l-Histidine decarboxylase, Hdc), has shed light on a putative involvement of this monoamine on the pathophysiology of tic and related disorders and fostered the development of coherent animal models [2]. Although HA-deficient rodents display markedly increased tic-like stereotypies following amphetamine administration, neither underlying nor predisposing differences in the open field test have been reported in quantitative measure…