dendrite outgrowth and patterning

Question 1

what is a dendrite

Answer 1

branched projections of a neuron that act to propagate the electrochemical stimulation received from other neural cells to the cell body or soma from which the dendrites project.

Question 2

are dendrites diverse?

Answer 2

Yes. they are very diverse.

Question 3

where are dendrites targeted?

Answer 3

they are targeted to specific nuclei, where they synapse with axons

Question 4

how do the secretory and endocytic systems affect dendrite outgrowth and patterning

Answer 4

allow coordinated secretion of cellular components to control dendritic outgrowth and arborization

Question 5

how do microtubule-based polarized trafficking of vesicles affect dendrites outgrowth and branching

Answer 5

transport a substantial amount of proteins and lipid to the distal dendrites.

Question 6

self-avoidance

Answer 6

branches from the same neuron recognize and repel each other, leading to branch separation and/or even spreading across the territory

Question 7

what does self-avoidance ensure?

Answer 7

orderly projection of sensory and synaptic inputs for efficient and unambiguous signal processing

Question 8

tiling

Answer 8

complete but non-overlapping coverage of a receptive field by arbors of a functionally related group of neurons

Question 9

what does tiling do?

Answer 9

allows neurons of the same class to cover entire dendritic field completely and non-redundantly

Question 10

heteroneural overlapping

Answer 10

dendrites from different types of neurons share overlapping dendritic fields.

Question 11

what does heteroneural overlapping do/

Answer 11

allows different neuronal types to process different sensory or synaptic inputs in the dendritic field.

Question 12

how do isoneuronal dendrites know not to make contact

Answer 12

this is a contact-depedent repulsion mechanism based on DsCam molecules

Question 13

what are DsCams?

Answer 13

they are a family of cell adhesion molecules that mediates contact-dependent isoneuronal repulsion through gene-splicing. they are required for self-avoidance in dendrites.

Question 14

what mediates self-avoidance in mammals

Answer 14

protocadherins

Question 15

is Dscam required for tiling?

Answer 15

no.

Question 16

what mediates tiling?

Answer 16

Tricorned kinase (TRC) and Furry (FRY)

Question 17

what is abrupt?

Answer 17

BTB-Zinc finger protein that suppresses dendritic complexity. only expressed on class I da neurons

Question 18

what does cut do?

Answer 18

expressed in da neurons. increases the complexity of arbors.

Question 19

what does knot do?

Answer 19

expressed in IV da neurons. increases complexity of arbor. 
increases the complexity in class I and II

Question 20

how do neurons acquire type specific dendritic arbors?

Answer 20

by combinatorial expression of different mediators of arborization

Question 21

what are the possible ways for dendrites targeting?

Answer 21

dendrites first, axons first or both at same time.

Question 22

how are dendrites targeted?

Answer 22

they reach the nuclei first, the axons infiltrate.

Question 23

what molecules are expressed for matching axons and dendrties

Answer 23

teneurins

Question 24

what else mediates dendritic arbor formation and localization

Answer 24

semaphorin gradients in the nuclei, properly orient dendrits.

Question 25

what mechanisms regulate dendrite targeting

Answer 25

intrinsic factors (TF) pre-specify targeting. interactions between pre and post synaptic partners as well

Question 26

what is involved in the process of dendrite development and morphogenesis

Answer 26

outgrowth and branching 
self-avoidance and tiling
diversity and complexity 
guidance and targeting 
scaling
remodeling 
activity-dependent regulation