Developmental Neurobiology Lecture Notes

Flashcards for lecture review.

Retinal wave activity in normal mice

Activity is highly correlated within each eye, but not between eyes.

Ventricular system

In the adult nervous system, the lumen of the neural tube persists as the ventricular system.

How Agrin promotes the clustering of acetylcholine receptors specifically at NMJ synapses

Agrin inhibits dispersal signals mediated by Cdk5 and Nestin

Radial glia in the developing cerebral cortex

They serve as a substrate for migration of newly postmitotic neurons.

Sonic Hedgehog (Shh) in mammalian CNS

Shh binds directly to Patched (Ptch) present in primary cilia.

Factors Contributing to Poor Regenerative Capacity in the Adult CNS

Chondroitin sulfate proteoglycans produced by reactive astrocytes and Increased KLF4 expression in mature CNS neurons

MECP2 null mice (Rett Syndrome model)

They show a CP shifted earlier in development, with early onset and early closure.

Transcription factor X expressed in radial glia

Over-expression of factor X in E14.5 radial glia increases layer 5 neurons and decreases layer 4 neurons and Knocking out factor X in E13.5 radial glia increases layer 4 neurons and decreases layer 5 neurons.

Neuronal identity regulated by extrinsic factors

Neurotransmitter identity of sympathetic neurons is regulated by CNTF and LIF released from the foot pad tissue.

Environmental factor that can cause developmental brain disorders

maternal immune activation, perinatal brain injury, fetal alcohol exposure, and iron deficiency

Neuronal Polarity

Microtubules in the axon are less stable than microtubules in the other neurites.

Postsynaptic excitability drives the developmental switch to inhibitory GABA

Blocking voltage-gated calcium channels delays the loss of GABA-induced excitation and KCC2 expression increases in cultures treated with KCl (which increases excitability).

Development of the neural crest (NC)

NC cells are initially present in the lateral margin of the neural plate, NC cells become terminally differentiated upon completion of their migration, NC cells generate only neurons and glial cells in the peripheral nervous system and NC cells develop from mesoderm.

Network activity over development

sparse, decrease, increase

Molecule overexpression likely to increase neuron generation at the expense of radial glia

Neurogenin 2

Gastrulation

occurs before the implantation.

Impact of blocking Bax in axons of thalamocortical neurons

Long range (millimeter long rearrangements)

Axon growth on extracted cell membranes

The signal is a repulsive cue from anterior tectum to temporal RGCs because only boiling anterior tectum stripes disrupts specific growth.

Neural induction

It is an example of tissue-tissue interactions that result in the determination of cell fates and Prospective forebrain is derived from the ectodermal tissue that lies above the head mesoderm (prechordal plate).

Axon behavior around Netrin1-secreting area

It will depend on the relative levels/activities of the two receptors within the axons, as the two receptors elicit distinct responses.

Experimental results supporting neural activity regulates cell death in the CNS

The amount of activity in different cortical areas negatively correlates with the amount of apoptotic cells and Blocking neural activity on one side of the whisker pad increases active caspase3 in the contralateral hemisphere.

Findings NOT an example of somatic mutations causing brain disorders

Mutations in the MECP2 gene in father's sperm causes Rett Syndrome in his daughter.

Factors determining responses to the environment within a navigating growth cone

The concentration of Ena protein, which promotes actin filament polymerization, The expression level of transmembrane receptors, such as EphB in the growth cone, The activity of Rac and Calcium concentrations in the growth cone

Effect of engineering hair follicles to express NGF on DRG neurons

Less nociceptive neurons would undergo apoptosis because they now have an additional source of neurotrophins and Nocieptive neurons would target both the skin and hair follicles.

Effect of overexpressing plexinA4 in M1 RGCs

M1 RGCs would fail to cross the ON sub-layer and therefore fail to form synapses in the OFF layer.

Neurons NOT normally produced in the adult mouse

ventral horn neurons in the spinal cord

Statements NOT correct about regionalization

Strong Wnt signaling in early neural plate provides a coarse caudal identity, Secondary organizers produce morphogens, which form subdivisions or polarity of the surrounding neural tissues and Sonic hedgehog produced by the notochord induces the floor plate within the neural tube, which also produces Sonic hedgehog.

Polymerization causing protrusion of the cell membrane

actin