The h current is a candidate mechanism for regulating the sliding modification threshold in a BCM-like synaptic learning rule.
نویسندگان
چکیده
Hebbian synaptic plasticity acts as a positive feedback mechanism and can destabilize a neuronal network unless concomitant homeostatic processes that counterbalance this instability are activated. Within a Bienenstock-Cooper-Munro (BCM)-like plasticity framework, such compensation is achieved through a modification threshold that slides in an activity-dependent fashion. Although the BCM-like plasticity framework has been a useful formulation to understand synaptic plasticity and metaplasticity, a mechanism for the activity-dependent regulation of this modification threshold has remained an open question. In this simulation study based on CA1 pyramidal cells, we use a modification of the calcium-dependent hypothesis proposed elsewhere and show that a change in the hyperpolarization-activated, nonspecific-cation h current is capable of shifting the modification threshold. Based on the direction of such a shift in relation to changes in the h current, and supported by previous experimental results, we argue that the h current fits the requirements for an activity-dependent regulator of this modification threshold. Additionally, using the same framework, we show that multiple voltage- and ligand-gated ion channels present in a neuronal compartment can regulate the modification threshold through complex interactions among themselves. Our results underscore the heavy mutual interdependence of synaptic and intrinsic properties/plasticity in regulating learning and homeostasis in single neurons and their networks under both physiological and pathological brain states.
منابع مشابه
In a Bcm-like Synaptic Learning Rule the H Current Is a Candidate Mechanism for Regulating the Sliding Modification Threshold
متن کامل
The h current is a candidate mechanism for regulating the sliding 1 modification threshold in a BCM - like synaptic learning rule
Corresponding Author 5 6 Daniel Johnston, Ph.D. 7 Center for Learning and Memory 8 The University of Texas at Austin 9 1, University Station Stop, C7000 10 Austin, TX 78712-0805, USA. 11 12 e-mail: [email protected] 13 Phone: 512-232-6564 14 Fax: 512-475-8000 15 16 17 † Present Address: 18 19 Rishikesh Narayanan, Ph.D. 20 Molecular Biophysics Unit 21 Indian Institute of Science 22 B...
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ورودعنوان ژورنال:
- Journal of neurophysiology
دوره 104 2 شماره
صفحات -
تاریخ انتشار 2010