Psych 3L03
Neuroscience Laboratory
PROJECT 1: BRAIN MECHANISMS FOR SKILL
LEARNING
LECTURE
AFTER THE EXPERIMENT
Selected information for the METHOD of OUR CURRENT
PROJECT
Method: subject, apparatus, procedure
- SUBJECTS:
- Long-Evan hooded rats,
male, N=4+2, body weight 250-300g
- care: 12:12 light-dark
cycle, food (deprived), water
- APPARATUS:
- Box: 65x15x80cm
Plexiglas box
- slit opening: ~ 1.5 cm
- plat form: 2 x 4 cm
- PROCEDURE:
- Training:
- task
- using preferred paw
- 5 days, 50 minutes
each
- movement
classification
- time interval between
reaches
- Recording:
- done 24 hrs after the
last training session
- anesthetize rat with
sodium pentobarbitol at 60 mg/kg body weight
- open scalp to expose
skull surface
- determine location of
bregma
- coordinates:
- recording AP1.6 mm,
ML2.0 mm, Depth 0.4 mm
- stimulating AP1.6
mm, ML2.5 mm, Depth 0.4 mm
- mark skull surface over
forelimb region of motor cortex and drill holes to expose brain
- position electrodes
on surface of brain and lower 400 mm into layer 2/3
- Using two bipolar
electrodes: one for stimulating and one for recording. Both are
constructed from stainless steel wire insulated with teflon
- record field
potentials evoked at different intensities of stimulation to construct
input/output function.
- A Grass Instruments
stimulator is used to deliver the stimulation.
- Stimulation consists
of a biphasic square pulse that is 100 msec in duration.
- Seven intensities (mA) are used: 63, 100,
159, 398, 631, 798, 1000
- The evoked field
potential is amplified (x2000) by a Grass Instruments amplifier and
digitized by a National Instruments analog to digital converter. The
digitized data is viewed and stored on the computer by LabView
software. The Labview output of
response amplitude was calibrated and displayed in the unit of mV.
- Histology
- Following the
recording the rat is perfused with 10% formalin and the brain is sectioned
on a cryotstat and stained with cresyl violet to verify the placement of
the electrodes (this wasn't actually done but should have been).