Nerve Growth Factor Differentially Affects Spatial and Recognition Memory in Aged Rats

Abstract

In rats, object discrimination depends on the integrity of the cholinergic system, thus it could be expected that nerve growth factor (NGF) can improve the behavior in aged subjects. The interactive effect of age and cholinergic improvement was assessed behaviorally in young and aged rats. Animals were injected by infusion of NGF into the lateral ventricles and they were tested in two behavioral tasks: an object-location and an object-recognition task. Spatial and recognition memory were assessed in an open field containing five different objects. Rats were submitted to six consecutive sessions. Both age-groups showed comparable habituation of exploratory response in Session 1-4. Discrimination index (DI) was calculated to assess responses to spatial change in Session 5 and object change in Session 6. Control young and aged rats were able to discriminate between familiar and novel object, however DI was lower in aged rats. Treatment with NGF induced decline of object discrimination in both age-groups. Different results were obtained in spatial displacement test. NGF was able to improve spatial memory in aged rats, but had no effect in young controls. These data confer on NGF potential role in improving spatial but not episodic memory in aged rats.

Chotosan, a Kampo Formula, Ameliorates Chronic Cerebral Hypoperfusion-Induced Deficits in Object Recognition Behaviors and Central Cholinergic Systems in Mice

“…These findings raise the possibility that facilitation of central cholinergic systems induced by CTS involves different mechanism(s) from those induced by THA and lead us to infer that cholinesterase inhibition is not always the mechanism responsible for the beneficial effect of CTS on P2VO-induced cognitive deficits in mice. However, further investigations using hippocampal tissues as an enzyme source may be required to more thoroughly answer questions concerning involvement of cholinesterase inhibition in the effects of CTS since cholinergic hypofunction impairs spatial cognitive behavior in which the hippocampus plays an important role (24,25,32).…”

The rat perirhinal cortex: A review of anatomy, physiology, plasticity, and function

“…These findings suggest that the hippocampus may have a role in this type of spatial learning. This form of learning appears to require expression of neurotrophins (Calamandrei et al, 2002;Niewiadomska et al, 2006) and exercise-induced enhancement of task performance has been associated with increases in hippocampal and perirhinal BDNF (Griffin et al, 2009). Furthermore, successful performance of the task is dependent on glutamatergic signalling through NMDA (Roullet et al, 1996;Usiello et al, 1998;Larkin et al, 2008) and AMPA receptors (Roullet et al, 2001).…”

Glia-Neurotrophic Factor Relationships: Possible Role in Pathobiology of Neuroinflammation-Related Brain Disorders

“…The way by which NGF modulates the immune response is however still not fully understood. NGF is known to support the growth of cholinergic neurons [ 125 , 126 ] and is also associated with embryonal development and the differentiation of peripheral neuronal cells [ 127 ]. Tuszynski has shown that intraparenchymal NGF infusions in rats prevented the degeneration of basal forebrain cholinergic neurons compared to vehicle-infused animals and cholinergic axons sprouted toward the NGF infusion in an apparent gradient-dependent manner [ 128 ].…”