par Joerg Bauer Il y a 15 années
537
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undordered thinking
Inabilty of filtering out unimportant stuff
Auditory
Visual
Perhaps missing sync in schizo causes 2 "I" s one of which is less dominant and only heard
Schizophrenia could be seen as a mild for of Epiliepsy
Drug work by decreasing efficacy of overactive sodium channel
Where
not stated
What?
Disrupted patterns of oscllations seen in Schizophrenia
What ...
Disrupted Oscillations
Lacking or malfunctioningNMDA receptors as causal
Where ...
Generally in the brain
Role in Interneurons
Book: Amygdala
Cole in fear conditioning
Book: Hippocampus
Role in Learning / LTP (Book 5 Chapter 1)
Hebbian Learning
Hebbian Synapse
A synapse that can be modiefied / made more efficient
In hebbian one neuron mightnot cause the other one to firebut be merely active at the same time
Modification of the synapse: Learing is increasing the efficiency of firing
By firing the post synaptic neuron is modified to work more efficient next time(more likely to fire)
Book 4 page 24Glutamate acts on many different types of receptor. One type, called the N-methyl-D-aspartate receptor (or NMDA receptor) is a neurotransmitter-gated ion channel that,unlike most other glutamate receptor-channels, is permeable to calcium ions. Inappropriate activation of this receptor induces toxic levels of intracellular calcium which canultimately lead to cell death (this toxic mechanism, termed excitotoxicity, is largely responsible for the brain damage induced by ischaemia and stroke)
role memory andLearning
Book 39 role in the initiation of memory consolidation
STM-->LTM
LTM
Strong Activation of NDMA-->LTM
STM
Activation of NDMA-->STM
Book 4 Initiation of Protein synthesis needed to maintain LTP
role several types learning
Book Classical Conditioning
Book 38: especially spatial learning
Book 4 NMDA is a receptor in Hipporcampal Glutamatergic neurons=a Glutamate gated Ion channel
Book 4 Page24-NMDA receptor is malregulated it can be toxic
Book: The dual role of the NMDA receptor as an activity coincidencedetector and gateway for calcium entry during the induction of LTP
Book5: It is the influx of calcium ions into the postsynaptic cell, via the NMDA channel, that triggers the biochemical cascade that leads to the increase in synaptic efficiency
Book 5 page 35: NDMA receptor acts as a conincidence detector– it opens only when there is a conjunction of neurotransmitter in the synaptic cleft and a critical level of depolarization in the postsynaptic neuron, a temporal pairing of presynaptic and postsynaptic activation: a Hebbian synapse.
Book 4 Glutamate: The most widespread excitatory neurotransmitter in the brain but active i.e. in the hippocampus
Book 4 page 23:and aspartate excite virtually all neurons in the brain and spinal cord. Upon release from aglutamatergic terminal, glutamateis inactivated by reuptake intothe presynaptic and postsynaptic neurons
Role in the singalling of elctrical synapsesbook 4 page 14
What do they do?
Book: Current Fuction is only Speculative: Current data suggest that the role of gap junctions is to facilitate instantaneous electrical rhythmicity in populations of neurons, if not whole brain structures. It has even been speculated that ultra-high frequency oscillations represent the ‘mind’ itselfBook: Whilst the function of these gap junction oscillations remains amystery, it has been proposed that in the cortex and hippocampus they may be implicated in cognitive processing, sensory perception and certain forms of distributed memory formation."
Book: What and where Elctrical Synapses produces Oscillations:"In the retina of the eye, for example, they are involved in the local integration of electrical activity between ensembles of retinal cells. Elsewhere in the brain they are involved in the generation of high-frequency electrical oscillations, similar to those seen during an epileptic seizure.
Cognitive processing
Distributed Memoryformation
If whole modules are distributed I.e. an emotional memory and the emotion itself the firing of thosestructures may need to besynchronized.
If memory is ditributed, what belongs together has to be signalled somehow
Were do electircal synapses exist
Role in In hippocampus and Cortex
Role in the retina
