Muscarinic suppression in stratum radiatum of CA1 shows dependence on presynaptic M1 receptors and is not dependent on eVects at GABAB receptors
نویسندگان
چکیده
Cholinergic modulation of synaptic transmission is vital to memory processes and may be responsible for setting network dynamics in the hippocampus appropriate for encoding of information. Sheridan and Sutor (1990) found evidence suggesting M1 receptors cause presynaptic inhibition of glutamatergic transmission, while Dutar and Nicoll (1988a) research supports a role of the M2 receptor. We examined muscarinic inhibition of fEPSPs in stratum radiatum of mice lacking m1 subtype receptors (KO) compared to wild type (WT) controls. WT mice exhibit greater suppression of transmission by muscarine as compared to KO in a dose dependent fashion. Oxotremorine shows no signiWcant diVerence in suppression between WT and KO, while MCN-A-343, an M1 agonist, exhibits a signiWcant diVerence between KO and WT, with KO showing no suppression. One hundred micromolar SGS-742, a selective GABAB antagonist, fails to aVect either normal transmission or muscarinic suppression in either WT or KO suggesting that diVerences in suppression between the groups is not attributable to diVerences in GABAB receptor activation due to muscarinic activation of GABAergic interneurons. These Wndings support a role for presynaptic m1 mAChRs in modulation of synaptic transmission in CA1, but indicate that other muscarinic receptor subtypes, such as M2, are also involved in suppression of synaptic potentials. 2005 Elsevier Inc. All rights reserved.
منابع مشابه
Muscarinic suppression in stratum radiatum of CA1 shows dependence on presynaptic M1 receptors and is not dependent on effects at GABA(B) receptors.
Cholinergic modulation of synaptic transmission is vital to memory processes and may be responsible for setting network dynamics in the hippocampus appropriate for encoding of information. found evidence suggesting M1 receptors cause presynaptic inhibition of glutamatergic transmission, while research supports a role of the M2 receptor. We examined muscarinic inhibition of fEPSPs in stratum rad...
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