DEFINATION:

Memory is the storage of acquired knowledge for later call.

MEMORY TRACES: Memory is stored in brain by changing basic

sensitivity of synaptic transmission b/w neuron as a result of previous

neural activity . The new or facilitated pathway are c/d memory

traces .

MEMORY

POSITIVE MEMORY: Information causes important consequences such as pain or pleasures.NEGATIVE MEMORY: Brain has capability to learn to ignore information that is of no consequence.

OTHER TERMS ARE: HABITUATION.

SENSITIZATION.

TYPE OF MEMORY

EXPLICIT : Also c/d DECLARATIVE memory , associated

with consciousness. DIVIDED INTO

EPISODIC: Memory for events.SEMANTIC : Memory for facts , words rules etc.

IMPLICIT: Also c/d non declarative , doesn’t involve consciousness. It include skill , habit ,conditioned reflexes.

PHYSIOLOGICAL CLASSIFICATION

Explicit Memory and many forms of implicit memory involve the temporary storage of information in working or short memory which lasts for few seconds or minutes.

WORKING MEMORY

SHORT TERM: Memory lasts for seconds or at most

minutes. Example: One’s memory of 7 to 10 numerals in a phone number for a few sec/min.

INTERMEDIATE LONG TERM:

Memory lasts days to week .

LONG TERM MEMORY:

Memory once stores ,can be recalled up to years.

CLASSIFICATION WITH RESPECT TO TIME

CHANGE OF SHORT TERM INTO INTERMIDIATE LONG TERM

CHANGE OF SHORT TERM INTO INTERMIDIATE LONG TERM

1• Noxious stimulus.

2• Release of serotonin from facilitating inter neuron.

3• ↑ Cyclic AMP in presynaptic neuron.

4• Blockage of K+ channels in presynaptic neuron.

5• Prolongation of action potential in presynaptic neuron.

6• Ca2+ channels in presynaptic neuron kept open longer.

7• Ca2+ influx.

8• ↑ Output of transmitter from presynaptic neuron.

9• ↑ Post synaptic Potential in efferent neuron.

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• Enhanced Behavioral response to stimulus.

CHANGE OF SHORT TERM INTO INTERMIDIATE LONG TERM

1• Repetitious indifferent stimulus.

2• Closing of Ca2+ channels in presynaptic neuron.

3• Ca2+influx ↓

4• ↓ Output of transmitter from presynaptic neuron.

5• ↓ Post synaptic Potential in efferent neuron.

6• Reduced behavioral response to indifferent stimuli.

HABITUATION

↑ in vesicle release sites for secretion of transmitter

substance.

↑ in number of transmitter vesicle released.

↑in number of presynaptic terminals .

Change in structures of the dendritic spines that permit

transmission of stronger signals

STRUCTURAL CHANGES OCCUR IN SYNAPSES DURING DEVELOPMENT OF LONG TERM

MEMORY.

POSSIBLE PATHWAY FOR LONG TERM MEMORY.

(LONG TERM POTENTIATION)

Anterograde Amnesia.Retrograde amnesia .