Wiring up the brain

Question 1

Angevine and Sidman (1961)

Answer 1

Birth dating studies on rodents

• Cells tagged at birth with radioactively labelled thymidine incorporated into DNA.
• time progresses, tissue excised
• reterospective insight into movement trajectories of labelled cells.

Question 2

Noctor (2001)

Answer 2

GFP expressing retrovirus, stains for cells from infected progenitor. Image radial glia cells generating neurons and acting as scaffolds for their progeny

Question 3

Marsick (2011)

Answer 3

Chemoattraction.
NGF to DRG neurons in culture - increase GC protrusion and actin polymerisation.
Extracellular gradients produced turning

Question 4

Brittis (1992)

Answer 4

Immunocytochemical localisation of CSPGs in retina, also showing neurons in vitro avoid areas of artificially laid CSPG

Question 5

Miller (1980s)

Answer 5

Work on somatogastric ganglion of lobster
Hyperpolarised cells inactivate them, pattern generation continues when any cell other than endogenous bursters are inactivated.

Question 6

Butt (2008)

Answer 6

Tamoxifen inducible cKO of homeobox tf Nkx2-1 in telencephalic progenitors regulates interneuron specification. Early loss - less MGE cortical interneurons, more LGE MSNs. Animals develop seizures.

Question 7

Sperry (1963)

Answer 7

Retinotectal system of newt. Sectioned optic nerves, eyes rotated 180deg. Nerves guided back to original site of termination - intricate chemical codes under genetic control guide axons

Question 8

Grove (2012)

Answer 8

FGF8 added through in utero electroporation and reduced, watch S1 move along horizontal axis

Question 9

Autism phenotype

Answer 9

• abnormal reciprocal social interactions
• Communication defecits
• Repeititive behaviours with restricted interests

Question 10

Twin study inheritance for Autism

Answer 10

90% concordance between monozygotic twins

Question 11

Silverman (2010)

Answer 11

BTBR inbred mouse model - mGluR5 antagonist reduced repetitive self-grooming

Question 12

How to test for sociality in autism mice?

Answer 12

Measure nose-nose sniffing, chasing, mounting, wrestling.

Question 13

Geschwind (2016)

Answer 13

PM genome-wide transcriptome analysis. ASD associated with dysregulation of non-coding long RNAs- SOX5 tf involved in neuron fate specification contributes to this dysregulation.