Synapse Formation

What is the primary mechanism driving the first phase of synapse formation?

Activity-dependent process
Adhesive and cell-cell recognition mechanisms (correct)
Genetically programmed process
Experience-dependent synapse formation

What is the purpose of the excess synapses formed during activity-independent synapse formation?

To provide a backup for potential neuronal damage
To increase the strength of synaptic connections
To facilitate further refinement through activity-dependent pruning (correct)
To enhance the speed of neural transmission

What is the role of critical periods in activity-dependent synapse refinement?

To inhibit the pruning of excess synapses
To regulate the formation of initial synaptic connections
To regulate the plasticity in several systems (correct)
To enhance the strength of synaptic connections

What is the neurobiological underpinning of the Nature vs Nurture debate?

Activity-dependent vs activity-independent synapse formation (A) Signup and view all the answers

What is the primary function of the second phase of synapse formation?

To refine the initial distribution of synaptic connections (B) Signup and view all the answers

What is the effect of drugs like tetrodotoxin on the first phase of synapse formation?

They have no effect on the first phase of synapse formation (B) Signup and view all the answers

What is the primary purpose of the formation of extra synapses in neural circuits?

To fine-tune precise patterns of connectivity by epigenetic mechanisms (B) Signup and view all the answers

Where do Retinal Ganglion Cells (RGCs) project their axons to?

Lateral Geniculate Nucleus, Superior Colliculus, and Pretectum (C) Signup and view all the answers

What is the characteristic of the layers in the Lateral Geniculate Nucleus (LGN)?

Each layer receives input from only one eye (C) Signup and view all the answers

What is the characteristic of Ocular Dominance Columns in the Cortex?

Neurons receive input from one eye only (D) Signup and view all the answers

What is the result of closing one eye of a juvenile cat in the classic experiment by Hubel and Wiesel?

Almost all of V1 responds only to the open eye (A) Signup and view all the answers

What is the conclusion of the experiment by Larry Katz on the formation of Ocular Dominance Columns?

The formation of Ocular Dominance Columns does not require activity (C) Signup and view all the answers

What is the characteristic of Strabismus?

Children cannot align their eyes properly or fuse the images from the two eyes (D) Signup and view all the answers

What is a common consequence of strabismus in children if left untreated?

Permanent vision loss in one eye (D) Signup and view all the answers

What is necessary for the sorting of LGN into eye-specific layers?

Spontaneous activity in retinal ganglion cells (B) Signup and view all the answers

According to the proposed model, what happens to the inactive axons from the left eye?

They retract (B) Signup and view all the answers

What is the main role of visual experience during the critical period in the visual system?

To reinforce and augment an already appropriately situated basic set of connections (A) Signup and view all the answers

What is the characteristic of neuromuscular synapses in the mature motor system?

Each fiber is innervated by a single motor neuron (D) Signup and view all the answers

What is the determining factor in the winner of the competition between axons at the NMJ?

Differential activity by competing inputs (A) Signup and view all the answers

What is the effect of complete block of activity on synapses at the NMJ?

Synapses remain intact (B) Signup and view all the answers

What is the primary consequence of asynchronous activity at the NMJ during development?

Synaptic elimination (B) Signup and view all the answers

At birth, what is the characteristic of motor neuron action potential activity?

Temporally correlated (C) Signup and view all the answers

What is the proposed mechanism of synapse elimination at the NMJ?

All of the above (D) Signup and view all the answers

What is the role of activity in the formation of ocular dominance columns in the visual system?

Not required for formation, but plays a role in maintenance (D) Signup and view all the answers

What is the characteristic of synaptic strength in the context of balancing competition at the NMJ?

Strength is spread out evenly between all synapses (C) Signup and view all the answers

What is the function of the 'Synapse factor' in the proposed mechanism of synapse elimination?

Leads to disassembly of postsynaptic site and axon withdrawal (D) Signup and view all the answers

What is the characteristic of competitions between two individual motor neurons at the NMJ?

The winner is always the neuron with less connections already (C) Signup and view all the answers

What is the requirement for sorting of eye-specific projections in the Lateral Geniculate Nucleus (LGN)?

Spontaneous activity but not experience (B) Signup and view all the answers

What is the characteristic of motor neuron activity weeks after birth?

Each muscle fiber is innervated by multiple motor neurons and activity is no longer correlated (A) Signup and view all the answers