Cocaine-induced cerebral hemodynamic and neuronal function changes in vivo measured by laser Doppler flowmetry

In this study Laser Doppler Flowmetry (LDF) was used to characterize the effects of cocaine on the local cerebral blood flow (LCBF) in rat brains in vivo. Also, the comparison of LCBF transients (ΔLCBF(t)) elicited in the same animal in response to forepaw electrical stimulation was investigated before and after acute cocaine challenge to characterize the effects of the cocaine on the neural function. Our experimental results demonstrated that an acute cocaine administration (1mg/kg, i.v.) induced a increase of ∼ 20-30% in LCBF immediately following the cocaine administration. The mean arterial blood pressure (MABP) also increased to 133 mm Hg from a baseline of approximately 91 mm Hg. Both LCBF and MABP increases were temporal, and recovered to baseline 10-12 min and 4-6 min post-injection of cocaine, respectively. However, ΔLCBF(t) signal elicited by forepaw stimulation was quenched until 40 min after cocaine injection. Our results elucidated the time course of cocaine's acute cerebrovascular and neurological effects, which might provide a better understanding of the etiology of cocaine-related stroke and transient ischemic attacks explored previously in the human studies.