SYNAPSE FORMATION Flashcards
WHAT HAPPENS WHEN A GROWTH CONE BECOMES A PRESYNAPSE
FILOPODIA RETRACTION
MEMBRANE AND EC GLYCOPROTEINS ADDED
PRESYNAPTIC VESICLES, DENSE ECM, PSD, RECEPTORS ACCUMULATE IN THE CLEFT
CONTACTS MADE BY WHAT CAN INITIATE SYNAPSES
GROWTH CONE
AXON BRANCHES
DENDRITIC FILOPODIA
IN SOME NEURONS, PRE-ESTABLISHED ……………………. MARK THE FUTURE SYNAPSE AND OTHER CONTACTS ARE ……………………
IN OTHER SITUATIONS, ……………….. CONTACTS, IF STABLE, RECRUIT SYNAPTIC COMPONENTS AND GO ON TO FORM FUNCTIONAL …………………..
SPECIALISED
INHIBITED
RANDOM
SYNAPSES
BROADLY, WHEN DOES SYNAPTOGENESIS OCCUR
AS AXONS REACH TARGETS
IS SYNAPTOGENESIS VARIABLE
YES
NON NEURONAL NEIGHBOURS CAN ……………….. SYNAPSES. PRE SYNAPTIC SPECIALISATION CAN BE INDUCED OR ……………….. BY GUIDE …………… CELLS - OFTEN ………………
THESE CAN ALSO BE THE SAME NEURONS THAT ……………… THE AXONS
SHAPE INHIBITED POST GLIA GUIDE
MANY OF THE MOLECULES THAT ARE INVOLVED IN SYNAPSE …………………… ARE ALSO INVOLVED IN …………… GUIDANCE. HOWEVER SOME ARE HIGHLY ……………….TO SYNAPSE FORMATION. THESE INCLUDE NEUREXINS AND …………………. WHICH ARE CELL ADHESION MOLECULES.
FORMATION
AXON
SPECIFIC
NEUROLIGINS
WHAT ARE NEUREXINS AND NEUROLIGINS
CELL ADHESION MOLECULES SPECIFIC TO SYNAPSE FORMATION
WHAT IS THE STRUCTURE OF NEUREXINS AND NEUROLIGINS
LARGE IC DOMAINS THAT CAN ASSEMBLE COMPONENTS OF THE ACTIVE ZONE AND POST SYNAPTIC DENSITY
NRX AND NL ALLOW SPATIAL SEGREGATION OF DIFFERENT ……………………/……………………..
INDIVIDUAL NEURONS CAN HAVE BOTH EXCITATORY AND INHIBITORY ……………..
INPUTS
OUTPUTS
INPUTS
WHAT CLINICAL ASSOCIATIONS DO NEUREXINS AND NEUROLIGINS HAVE
AUTISM
SCHIZOPHRENIA
WHAT DO EXCITATORY SYNAPSES HAVE THAT INHIBITORY SYNAPSES DO NOT
MORE DENSE POST SYNAPTIC DENSITIES
DURING DEVELOPMENT, DIFFERENTIAL ………………. OF MULTIPLE MEMBERS OF ………….. AND NL FAMILIES ALLOWS DIFFERENT PRE SYNAPTIC NEURONS TO ………………. BETWEEN DIFFERENT ………….. SYNAPTIC PARTNERS.
EXPRESSION
NRX
SELECT
POST
DIFFERENTIAL LOCALISATION OF NLS ON THE POST SYNAPTIC CELL ALSO ALLOWS SEPARATED WHAT
INNERVATION BY EXCITATORY AND INHIBITORY PRE SYNAPTIC NEURONS
SINGLE NEURONS CAN HAVE MULTIPLE INPUTS
GIVE AN EXAMPLE
PURKINJE CELLS IN THE CEREBELLUM RECEIVE INPUTS FROM PARALLEL FIBRES, ML INTERNEURONS AND CLIMBING FIBRES IN A SPATIALLY RESTRICTED MANNER
DESCRIBE ANOTHER FEATURE OF SYNAPSES
PLASTICITY
WHAT ARE THE MODELS OF SYNAPSE FORMATION
- DENDRITIC SPINES DEVELOP INDEPENDENTLY OF PRE SYNAPTIC INPUTS
- PRESYNAPTIC INPUTS INDUCE SPINE FORMATION
- DENDRITIC FILOPODIA INDUCE SYNAPSES IN AXONS GROWING PAST
IN ALL CASES PRE AND POST SYNAPTIC CELLS MUST WORK TOGETHER
WHAT OCCURS IN ASSEMBLY OF SYNAPTIC COMPONENTS
CONTACTS (VIA CAMS OR SOLUBLE FACTORS EG WNT) BETWEEN DENDRITE AND AXON TRIGGERS INTRACELLULAR SIGNALS VIA CALCIUM FLUX.
THIS PROMOTES RECRUITMENT OF SCAFFOLDING PROTEINS PROVIDING FRAMEWORK FOR FORMATION OF COMPLEXES FORMING THE ACTIVE ZONE AND POST SYNAPTIC DENSITY
GIVE EXAMPLES OF A SCAFFOLDING PROTEIN INVOLVED IN ASSEMBLY OF SYNAPTIC COMPONENTS
CASK
PSD-95
WHY IS THE NEUROMUSCULAR JUNCTION A GOOD MODEL FOR SYNAPSES
EASILY ACCESSIBLE
SIMPLE
VERY LARGE
NOTABLE FOR ABILITY OF THE MOTOR TERMINAL TO ORGANISE COMPONENTS OF THE POST SYNAPTIC CELL
BEFORE INNERVATION OF A NMJ WHAT IS THE DENSITY OF ACETYLCHOLINE RECPTORS
LOW DENSITY
IN TERMS OF ACH RECEPTORS AND OTHER CHANNELS, WHAT DOES INNERVATION LEAD TO
PROGRESSIVE CLUSTERING TO THE EXTENT THAT EVENTUALLY ONLY FOUND BENEATH NERVE TERMINALS
MOTOR NEURON ………………. CONTACT MYTOTUBULES AT ……………. AND NEW ……………. CLUSTERS CAN BE BORN AT SITES WITHOUT PRE CLUSTERS. THIS …………….. CLUSTERING IS ACTIVITY …………………… SUGGESTING THAT MOTOR NEURONS SECRETE AN INDUCING FACTOR: ……………………
NEURITES RANDOM ACHR INDUCED INDEPENDENT AGRIN
WHAT ARE THE STAGES OF RECEPTOR CLUSTERING
- INITIALLY ACHR MRNA IS EXPRESSED AT LOW LEVELS IN MANY MYOTUBE NUCLEI AND ACHR CHANNELS ARE WIDELY DISTRIBUTED
- AGRIN RELEASED BY MN BINDS TO THE MUSCLE SPECIFIC KINASE (MUSK) COMPLEX WHICH AUTOPHOSPHORYLATES AND RECRUITS RAPSYN WHICH RECRUITS CLUSTERS OF ACHR
- OTHER FACTORS RELEASED BY THE SYNAPSING MN GROWTH CONE SUCH AS NEUREGULIN INDUCE ACHR EXPRESSION IN SYNAPTIC NUCLEI NEARBY
- ACH IS ALSO RELEASE BINDING TO ACHR
- WHEN ACTIVITY IS NOT ACCOMPANIED BY AGRIN, ACHR EXPRESSION AND CLUSTERING ARE INHIBITED.
