Disruption of cerebellar cholinergic system in hypoxic neonatal rats and its regulation with glucose, oxygen and epinephrine resuscitations

l-Hypaphorine and d-hypaphorine: Specific antiacetylcholinesterase activity in rat brain tissue

Acetylcholinesterase (AChEis) inhibitors are used to treat neurodegenerative diseases like Alzheimer's disease (AD). l-Hypaphorine (l-HYP) is a natural indole alkaloid that has been shown to have effects on the central nervous system (CNS). The goal of this research was to synthesize l-HYP and d-HYP and test their anticholinesterasic properties in rat brain regions. l-HYP suppressed acetylcholinesterase (AChE) activity only in the cerebellum, whereas d-HYP inhibited AChE activity in all CNS regions studied. No cytotoxic effect on normal human cells (HaCaT) was observed in the case of l-HYP and d-HYP although an increase in cell proliferation. Molecular modeling studies revealed that d-HYP and l-HYP have significant differences in their binding mode positions and interact stereospecifically with AChE's amino acid residues.

Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges

Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.

The cholinergic system in the cerebellum: from structure to function

The cerebellar cholinergic system belongs to the third type of afferent nerve fiber system (after the climbing and mossy fibers), and has important modulatory effects on cerebellar circuits and cerebellar-mediated functions. In this report, we review the cerebellar cholinergic system, including cholinergic origins and innervations, acetylcholine receptor expression and distributions, cholinergic modulations of neuronal firing and synaptic plasticity, the cholinergic role in cerebellar-mediated integral functions, and cholinergic changes during development and aging. Because some motor and mental disorders, such as cerebellar ataxia and autism, are accompanied with cerebellar cholinergic disorders, we also discuss the correlations between cerebellar cholinergic dysfunctions and these disorders. The cerebellar cholinergic input plays an important role in the modulation of cerebellar functions; therefore, cholinergic abnormalities could induce physiological dysfunctions.

Long term effects of neonatal hypoglycaemia on pancreatic function

OBJECTIVES

Low blood glucose in neonates predisposes to long term pancreatic damage. We focused on evaluating long term consequences of neonatal hypoglycaemia in pancreatic functions.

METHODS

Pancreatic function was analysed by measuring DNA/protein synthesis, glucose/ATP uptake in vitro. Gene expression of Pdx1, NeuroD1, Pax4, Bax, caspase 3, Beclin1 were done. Muscarinic receptors were analysed by radio receptor assay.

RESULT

Overall pancreatic efficiency was reduced in one-month-old rats exposed to neonatal hypoglycaemia as indicated by decreased DNA/protein synthesis and glucose/ATP uptake in vitro. Both Pdx1 and Neuro D1 expression were significantly down-regulated whereas Pax4 was up-regulated. Up-regulated Bax, caspase 3 and beclin1 along with reduced muscarinic receptors accounts for activation of cell death pathways.

CONCLUSION

The study revealed a drastic reduction in pancreatic functions along with activation of apoptotic factors in one month old rats exposed to neonatal hypoglycaemia.