PHARMACOLOGICAL EFFECTS PRODUCED BY INTRACEREBRAL INJECTION OF DRUGS IN THE CONSCIOUS MOUSE

TLDR

A method for studying central effects of intracerebral drug injections in conscious mice has been described. Intracerebral injection of diverse drugs induces generalized effects such as tail positioning changes, stupor, hyperexcitability, and tachypnoea. Observed drug effects in mice matched those seen in other species; acetylcholine and methacholine induced akinetic seizures and depression (methacholine also causing lacrimation and salivation), atropine produced piloerection, heightened sensitivity, clonic convulsions, and scratching, hexamethonium caused Parkinsonian‑like tremors and vasodilatation, adrenaline led to hyperexcitability, exophthalmos, stupor, and death from pulmonary oedema, (+)-methylamphetamine caused only piloerection and heightened activity, ergotamine decreased sensitivity and caused micturition and stupor, and ergometrine induced clonic convulsions, piloerection, defaecation, and stupor.

Abstract

A method has been described for the study of the central effects produced by the intracerebral injection of drugs in the unanaesthetized mouse. The effects observed were in good agreement with those obtained after similar injections in cats, dogs and human beings. After intracerebral injection, drugs of diverse structure produced certain generalized effects: changes in positioning of the tail, stupor, hyperexcitability and tachypnoea. Both acetylcholine and methacholine produced an akinetic seizure and depression, but the latter compound also caused lacrimation and salivation. Atropine produced piloerection, increased sensitivity to sound and touch, clonic convulsions and scratching, whereas hexamethonium caused Parkinsonian-like muscle tremors and peripheral vasodilatation. After adrenaline, hyperexcitability, exophthalmos, stupor and death from pulmonary oedema were observed, but (+)-methylamphetamine produced only piloerection and exaggerated activity in response to sound and touch. Ergotamine caused a decreased sensitivity to sound and touch, micturition, and stupor, while ergometrine caused clonic convulsions, piloerection, defaecation and stupor.