PubMed Health⌕ Search

Biomedical subjects

Diana Jerusalinsky

Publications and source records attributed to Diana Jerusalinsky.

3 recordsLinked to original sources

Amplicon vectors as outstanding tools to study and modify cognitive functions.

This review summarizes recent data on the use of HSV-1-based amplicon vectors for in vivo gene delivery to the brains of rats and mice to study and modify behaviour. Here we describe studies that have focused on cognitive functions like learning and memory. In addition, the use of amplicons in other behavioural studies, like addiction, social interaction, anxiety and stress, will be briefly updated. Several remarkable findings have been achieved, thanks to the use of these very efficient and non-toxic naturally neurotropic vectors, most particularly the consistent observation that genetic manipulation of a rather limited number of neurons in restricted regions of the brain, could result in significant behavioural changes, a notion that is therefore emerging as a common unifying hypothesis, thanks to these works.

Animals↗

Role of hippocampal M1 and M4 muscarinic receptor subtypes in memory consolidation in the rat.

Muscarinic receptors in the hippocampus are relevant to learning and memory, but the role of each subtype is poorly understood. Muscarinic toxins (MTs) from Dendroaspis snakes venom are selective for muscarinic receptor subtypes. MT2, a selective agonist for M(1) receptors, given into the hippocampus immediately after training, improved memory consolidation of an inhibitory avoidance task in rats, whereas the antagonist pirenzepine was amnestic, supporting a facilitatory role of M(1) receptors. Instead, MT3, a selective antagonist at M(4) receptors, caused amnesia. Neither M(1) nor M(4) receptor appeared involved in habituation to a new environment. Thus, our results suggest that memory consolidation of an inhibitory avoidance task in the rat involves the participation of both M(1) and M(4) hippocampal receptors, with a positive modulatory role.

Animals↗

Effects of muscarinic toxins MT1 and MT2 from green mamba on different muscarinic cholinoceptors.

MT1 and MT2, polypeptides from green mamba venom, known to bind to muscarinic cholinoceptors, behave like muscarinic agonists in an inhibitory avoidance task in rats. We have further characterised their functional effects using different preparations. MT1 and MT2 behaved like relatively selective muscarinic M1 receptor agonists in rabbit vas deferens, but their effects were not reversed by washing or prevented by muscarinic antagonists, although allosteric modulators altered responses to MT1. Radioligand binding experiments indicated that both toxins irreversibly inhibited [3H]N-methylscopolamine binding to cloned muscarinic M1 and M4 receptors, and reduced binding to M5 subtype with lower affinity, while they reversibly inhibited the binding of [3H]prazosin to rat cerebral cortex and vas deferens, with 20 fold lower affinity. High concentrations of MT1 reversibly blocked responses of vas deferens to noradrenaline. MT1 and MT2 appear to irreversibly activate muscarinic M1 receptors at a site distinct from the classical one, and to have affinity for some alpha-adrenoceptors.

Animals↗