Age-related decline in cholinergic synaptic transmission in hippocampus

Neurobiol Aging. 1993 Sep-Oct;14(5):509-15. doi: 10.1016/0197-4580(93)90110-w.


Age-dependent changes in central nervous system (CNS) cholinergic synaptic transmission were studied in three age groups of Sprague-Dawley and Fischer 344 rats: 1- to 2-month-old, 8- to 10-month-old, and 18- to 23-month-old. Utilizing intracellular recording techniques and the in vitro hippocampal slice preparation, we report an age-related decline in central cholinergic transmission as a function of age. Slow excitatory postsynaptic potentials (slow EPSPs) were reduced approximately 60% in aged (18- to 23-month-old) compared to younger (1- to 2-month-old) animals. The response of the postsynaptic membrane to the muscarinic agonist, carbachol (0.3 microM), was also reduced with age. These changes were not accompanied by a global decline in muscarinic receptor function since two additional measures of cholinergic function were not changed with age. Both presynaptic inhibition of fast excitatory synaptic transmission and postsynaptic inhibition of the afterhyperpolarization (AHP) following a train of spikes were not changed during aging. Our results suggest that a primary functional decline in central cholinergic mechanisms during aging may be a specific reduction in central cholinergic synaptic transmission.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology*
  • Animals
  • Carbachol / pharmacology
  • Electrophysiology
  • Evoked Potentials / drug effects
  • Evoked Potentials / physiology
  • Hippocampus / drug effects
  • Hippocampus / physiology*
  • In Vitro Techniques
  • Male
  • Parasympathetic Nervous System / drug effects
  • Parasympathetic Nervous System / physiology*
  • Rats
  • Rats, Inbred F344
  • Rats, Sprague-Dawley
  • Receptors, Muscarinic / drug effects
  • Receptors, Presynaptic / drug effects
  • Receptors, Presynaptic / physiology
  • Synapses / drug effects
  • Synapses / physiology*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*


  • Receptors, Muscarinic
  • Receptors, Presynaptic
  • Carbachol