Enhancement of spatial navigation ability in older rats following chronic administration of the alpha2 noradrenergic antagonist piperoxane

Abstract

The noradrenergic system of the locus coeruleus has been implicated in a variety of processes including reinforcement, attention, and acquisition and retention of learned behaviors. Its dense projections, some of which are shared by the cholinergic system , provide an ideal network within which to study the cognitive impairments related to aging. The current investigation explored the effects of piperoxane, an <X2 noradrenergic receptor antagonist, on the performance of 18-and 24-month-old rats in the Morris water maze and a step-down passive avoidance task. Piperoxane injections (3 mg/kg, IP) facilitated the performance of the 18-month-old animals to levels comparable to those of the 8month-old saline controls in constant-start, novel-start, and goal rotation testing variations of the Morris water maze. With the exception of the 24-month-old saline control group, all rats displayed retention on the step-down passive-avoidance task when tested 24 hours after training.

An Examination of the Effects of 5-Methoxy-N,N-di(iso)propyltryptamine Hydrochloride (Foxy) on Cognitive Development in Rats

“…Spatial navigation-Morris water maze (Morris, 1984).-With the exception of the number of trials in goal-rotation testing (see below), all spatial testing was similar to that described by Compton, et al (1997) and occurred in a circular swimming pool 183 cm in diameter and painted flat white. Water was filled to a depth of 30 cm and made opaque by the addition of a nontoxic paint (Sargant Art, Hazelton, PA).…”

“…The tasks described below were chosen for their sensitivity in distinguishing between spatial memory impairment (see Compton, Dietrich, & Smith, 1997) and nonspatial memory impairment (e.g., Compton, 2004).…”

Long term consequences on spatial learning-memory of low-calorie diet during adolescence in female rats; hippocampal and prefrontal cortex BDNF level, expression of NeuN and cell proliferation in dentate gyrus

“…Escape latency (time to reach the platform) was recorded in each trial. On the third day, the escape latency under 10 s was considered as the indicator of learning (Compton et al, 1997). On the fourth day, spatial memory test (probe test) was performed.…”

Differentiation of MDMA or 5-MeO-DIPT induced cognitive deficits in rat following adolescent exposure.

“…With the exception of the number of trials in goal rotation testing, all spatial testing was similar to that described by Compton, Dietrich, and Smith (1997) and occurred in a circular white acrylic plastic swimming pool 183 cm in diameter. Water was filled to a depth of 30 cm and made opaque by the addition of a nontoxic paint (Sargant Art, Hazelton, PA).…”