MCB 105 Section 2 Announcements No section next

MCB 105 Section 2

Announcements • No section next Monday (2/16) – Presidents’ Day • The papers assigned for next week will still be covered in the final, and could be relevant to your research proposal. • So, try to read them next week anyway, and let me know if you have any questions.

Amygdala and fear Monkey with Klüver– Bucy syndrome (1930 s)

Le. Doux: Two pathways to fear

Hypothalamus (PVN) Hypothalamus (LH) Periacqueductal gray or central gray (CG)

What was the important question in the field that the authors addressed in the paper?

• Briefly describe the general approach/training paradigm the authors used in this paper. • What was special about the CS stimulus they used?

Extracellular recordings and field potentials INTRACELLULAR Electrical stimulation (can also be auditory etc) EXTRACELLULAR This is meant to represent a large population of synapses and neurons.

Fig 1 A Unpaired Why is the unpaired control important?

Fig 1 B

Fig 1 C 1) Explain the similarities and differences between effects of training on CS-EPs vs freezing behavior 2) How do they know the increase in freezing in controls post-training is not due to the CS?

Fig 2

Explain tone-shock conditioning using Hebbian plasticity in amygdala circuits

LTP in amygdala Fear conditioning Enhanced auditoryevoked field potentials

What was the important question in the field that the authors addressed in the paper?

Optogenetics

IN which neurons do they put Ch. R 2? Where do they stimulate?

Fig 1 A-B

What is an additional control that they did?

Fig 1 C Holding potentiial: -60 m. V +40 m. V

Fig 1 D

Fig 2 A-F What is the difference between LTP and LTD protocol?

Fig 3 G

PAIRED CONDITIONING Tone LTP Shock Lateral Amygdala neurons Fear response OPTICAL LTD Tone LTP OPTICAL LTP Tone LTP Lateral Amygdala neurons Fear response

What two scenarios did the authors want to distinguish next? OPTICAL LTP REINSTATES A MEMORY Tone LTP Lateral Amygdala neurons Fear response OPTICAL LTP POTENTIATES OTHER INPUTS Tone ? ? LTP Lateral Amygdala neurons Fear response

Fig 3 A-F

3 G-3 K Role of LTP in fear conditioning?

Fig 4

Fig 5 A-D What additional step did they have to take for this experiment and why?

Fig 5 E-G What might this tell you about extinction?

Fig 5 H-K