Age-related plasticity impairmentspresynaptic mechanisms

• Autorzy: Liguez-Lecznar M.
• Języki publikacji: EN

Abstrakty

EN

The lecture will focus on age-related changes in expression of presynaptic proteins necessary for the neurotransmitter release as well as alterations of inhibitory/excitatory neurotransmitter balance and their influence upon the functional cortical plasticity. Age-related cognitive impairments may be linked to molecular changes in the synapse resulting in plasticity decline. In somatosensory cortex of aging mice we observe a decline of functional cortical plasticity induced by 3-days lasting classical conditioning, which could be linked to the altered excitatory-inhibitory balance that controls cortical excitability. This decline can be overcome by extended training. Analysis of mRNA and protein expression of several presynaptic markers controlling neurotransmission revealed decrease of synaptophysin, vesicular glutamate transporter-vglut2, glutamic acid decarboxylase-GAD67 and vesicular GABA transporter-VGAT protein, as well as mRNA for VGAT in aged mice barrel cortex. Moreover, due to significant decrease of glutamate concentration, the glutamate/GABA ratio, measured with HPLC, was decreased in the somatosensory cortex of aged animals.  Importantly, the impairment of conditioning-induced plasticity in aged animals coincided with the lack of GABA and GAD 67 increase after training. It may reflect the inefficiency of inhibitory mechanisms in aging brain to control increased excitation after training and to shape proper signal to noise ratio essential for the appropriate stimuli processing. We propose that the disequilibrium of excitation and inhibition in favour of inhibition may be the decisive factor for weakening the plastic potential of aging neurons and combined with insufficient GABA response to conditioning, contribute to the impairment of learning-dependent cortical plasticity. Supported by National Science Centre Grant: 2013/09/B/ NZ3/00540.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S24

Twórcy

autor

Liguez-Lecznar M.

• Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland