model system: sea hare ( aplysia californica ) behavior: the gill & siphon withdrawal reflex
DESCRIPTION
PART 4: BEHAVIORAL PLASTICITY #21: LEARNING & MEMORY of a SIMPLE REFLEX in APLYSIA II. model system: sea hare ( Aplysia californica ) behavior: the gill & siphon withdrawal reflex even more cell biology: learning & memory summary. PART 4: BEHAVIORAL PLASTICITY - PowerPoint PPT PresentationTRANSCRIPT
model system: sea hare (Aplysia californica) behavior: the gill & siphon withdrawal reflex even more cell biology: learning & memory summary
PART 4: BEHAVIORAL PLASTICITY#21: LEARNING & MEMORY of a SIMPLE
REFLEX in APLYSIA II
model system: sea hare (Aplysia californica) behavior: the gill & siphon withdrawal reflex even more cell biology: learning & memory summary
PART 4: BEHAVIORAL PLASTICITY#21: LEARNING & MEMORY of a SIMPLE
REFLEX in APLYSIA II
mechanistic analysis of classical conditioning convergence of CS & US in sensory neuron adenylyl cyclase (AC) = coincidence detector? sensitization:
Ca++ channels closed Ca++ not bound to calmodulin calmodulin not bound to AC some cAMP ...
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning convergence of CS & US in sensory neuron adenylyl cyclase (AC) = coincidence detector? associative learning:
Ca++ channels open Ca++ bound to calmodulin calmodulin bound to AC lots of cAMP ...
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
glutamate, excitatory transmitter activates N-methyl-D-aspartate (NMDA) receptor
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
glutamate, excitatory transmitter activates N-methyl-D-aspartate (NMDA) receptor no signal...
NMDA channel closed no Ca++ enters cell
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
glutamate, excitatory transmitter activates N-methyl-D-aspartate (NMDA) receptor signal...
glutamate binds to receptor postsynaptic membrane
depolarizes postsynaptic neuron fires test this model?
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning
aminophosphonovalerate (APV) block of NMDA receptor…
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning block NMDA receptor with APV during training
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning block NMDA receptor with APV during training associative synaptic facilitation
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning block NMDA receptor with APV during training associative synaptic facilitation NMDA receptor necessary
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
differential conditioning same result during training if
postsynaptic neuron: hyperpolarized Ca++ blocked
presynaptic neuron: PKA blocked Ca++
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning postsynaptic factors
implication that the postsynaptic neuron communicates with the presynaptic neuron
retrograde (backward) signaling evidence (not shown) – associative facilitation
mechanism in postsynaptic neuron changes signaling properties in the presynaptic neuron
neurons communicate in both directions but... what is the signal?
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning revised model
2 sites of CS-US coincidence presynaptic AC
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning revised model
2 sites of CS-US coincidence presynaptic AC postsynaptic
NMDA receptorgated channels
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of classical conditioning revised model
2 sites of CS-US coincidence presynaptic AC postsynaptic
NMDA receptorgated channels
retrograde signal(hypothetical)
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons terminology:
long-term memory (LTM) behavioral measure long-term facilitation (LTF) physiological measure
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training: siphon withdrawal
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training siphon withdrawal sensory EPSPs
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training siphon withdrawal sensory EPSPs S-current
(data not given)
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training siphon withdrawal sensory EPSPs S-current serotonin-induced
presynaptic transmitter release (data not given)
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training siphon withdrawal sensory EPSPs S-current serotonin-induced
presynaptic transmitter release (data not given)
presynaptic neuronal plasticity
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training serotonin substitutes for tail shock @ sensory
cell body LTF terminal STF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
distributed sensitization training serotonin substitutes for tail shock @ sensory
cell body LTF terminal STF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
serotonin induces LTF
intracellular signal protein synthesis (?) neural plasticity (?)
STF locally @ synapse
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
protein synthesis (?) transcription translation transport synapses
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
protein synthesis inhibited by blockers also block LTF
during serotonin application only not before or after... narrow temporal window
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
protein synthesis inhibited by blockers also block LTF
during serotonin application only not before or after... narrow temporal window
no block of STF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term synaptic facilitation in sensory neurons
protein synthesis inhibited by blockers also block LTF
during serotonin application only not before or after... narrow temporal window
no block of STF ... and does block LTM (behavior) protein synthesis necessary for LTM
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term sensitization / serotonin treatments
molecular changes in sensory neurons: persistent phosphorylation of existing proteins synthesis of new proteins growth of sensory neurons... neural plasticity
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term sensitization / serotonin treatments
molecular changes in sensory neurons: growth of sensory neurons... neural plasticity
visual examination axonal processes,
branching, varicosities
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term sensitization / serotonin treatments
molecular changes in sensory neurons: growth of sensory neurons... neural plasticity
visual examination axonal processes,
branching, varicosities
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term sensitization / serotonin treatments
molecular changes in sensory neurons: growth of sensory neurons... neural plasticity
model for synaptic restructuring / plasticity varicosities terminal active zones opposite for habituation
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory long-term sensitization / serotonin treatments
molecular changes in sensory neurons: growth of sensory neurons... neural plasticity
model for synaptic restructuring / plasticity varicosities terminal active zones
long-term increase in synaptic transmission what are the molecular mechanisms?
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
cAMP pathway implicated: cAMP injection ... S-current PKA inhibitors ... block serotonin-induced LTF serotonin application ... PKA catalytic subunit
cytoplasmic nuclear activity of genes:
immediate early (IEG), transcription factors late-responsive, leave nucleus
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
cAMP pathway implicated: cAMP response elements (CREs) on DNA CRE binding protein (CREB) phosphorylated by PKA...
CREBs IEGs IEGs late-responsive genes
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
single training event some PKA, STF distributed training more PKA... nucleus, LTF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
competition studies using injected CRE sequences block CREB binding & LTF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
competition studies using injected CRE sequences block CREB binding & LTF
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory molecular induction of LTF in sensory neurons
competition studies using injected CRE sequences block CREB binding & LTF
enhanced CREB + 1 serotonin application LTF structural enhancement
CREB essential for LTF & LTM similar findings in Drosophila (next chapter)
CELL BIOLOGY OF LEARNING & MEMORY
mechanistic analysis of long-term memory LTF molecular model
what proteins? how do they work? other 2nd messenger
cascades? homology (flies, mice)
CELL BIOLOGY OF LEARNING & MEMORY
middle-term memory... read the section on your own
CELL BIOLOGY OF LEARNING & MEMORY
defensive withdrawal reflex after stimulation (CS) of siphon, mantle, gill
shows non-associative learning properties habituation, dishabituation, sensitization
sensitization: reflex with preceding tail shock associative learning
reflex (CS) + paired shock (US) differential conditioning = CS1+ + US, CS2–
distributed training long-term memory
SUMMARY
tail shock sensitization interneuron serotonin release sensory neuron K current flow (out of cell) spike broadening synaptic facilitation cAMP cascade mediated sensory neuron transmitter release
SUMMARY
classical conditioning interneuron serotonin release sensory neuron tail shock US responses augmented by
concurrent CS signal... activity-dependent presynaptic facilitation postsynaptic process, NMDA receptor in motor
neuron
SUMMARY
long-term memory dispersed training protein synthesis-dependent cAMP & CREB IEGs IEGs late-response genes proteins neuron terminals neuronal plasticity
SUMMARY