@The Effect of Palmitic Acid on Spatial Learning and Extinction in Adult Male Rat (2007)

2022-04-28: reference:

@The Effect of Palmitic Acid on Spatial Learning and Extinction in Adult Male Rat (Hosseinzadeh et al. 2007) #

• The figures are a bit confusing to read, but learning was indeed enhanced. The english is also a bit broken xd.

• The Postsynaptic Density represents a major palmitoylated protein in the brain.

• The lipid modification is critical for PSD-95 clustering of AMPARs at excitatory synapses. Cycling(?) of palmitate on PSD-95 is augmented by calcium influx (via NMDAR) and can contribute to aspects of synaptic plasticity.

• In cultured hippocampal neurons, overexpression of PSD-95 accelerates development of excitatory synapses and selectively enhances clustering of AMPARs. Targeted disruption of PSD-95 causes severe abnormalities, such as LTP enhancement and LTD elimination???

• During brain development, NCAM1 is heavily polysialylated, while the developing brain has a high level of Ncam1, the adult brain has appreciable levels only in the areas that continually undergo structural reorganization and demonstrate synaptic plasticity (i.e. hypothalamus & hippcampus).

  • NCAM1 is transiently upregulated at the synapse during learning and memory.
  • Both resting and NGF-induced NCAM1 expression is dependent on the presence of an intact palmitoylation site within p75.
  • In cultured hippocampal neurons, inhibitors of protein palmitoylation reduced the synaptic clustering of GABA receptors.
    • Increased impulse flow in the septohippocampal GABAergic pathway facilitated enhanced cognition initiated by a muscarinic agonist.

• Differential palmitoylation directs the AMPA receptor-binding protein ABP to spines or to intracellular clusters
  • 500
  • Mutations of PSD-95 that abolish palmitoylation reduced the synaptic targeting of PSD-95 and its ability to interact with the ion channel Kv1.4
  • Non-palmitoylated GRIP is primarily intracellular. The addition of palmitic acid to ABP-L/GRIP1a anchors AMPAR at the membrane.
  • Nonpalmitoylated intracellular ABP-L/GRIP1a anchors AMPA receptors at extrasynaptic, intracellular locations