Table 1. Properties of the two main types of pyramidal neurons in turtle visual cortex.

Mean and standard deviation for all values.

Parameter	Type A	Type B
	(n = 80)	(n = 145)
Rheobase Current (pA):	33.9 ± 13.0	72.6 ± 19.3
AP Voltage Threshold (mV):	-38.9 ± 2.3	-40.2 ± 3.7
AP Height (mV):	64.7 ± 4.8	59.4 ± 5.2
Maximum AP Downslope (mV/ms):	-34.4 ± 8.6	-23.2 ± 5.0
AP half-width (ms):	2.2 ± 0.3	3.1 ± 0.6
Resting Membrane Potential (mV):	-53.2 ± 2.8	-65.8 ± 3.7
Input Resistance (MΩ):	423 ± 80	271 ± 56
AP Frequency Adaptation Ratio:	0.874 ± 0.104	0.499 ± 0.084
AP Duration at Threshold (ms):	59.9 ± 18.0	82.9 ± 47.5
AHP Time to Peak (ms):	56.2 ± 20.5	32.9 ± 15.5
AP Duration Increase (%):	14.6 ± 6.7	23.1 ± 7.7
AP Amplitude Decrement (%):	4.3 ± 3.4	1.0 ± 3.9
ISI Variability:	15.1 ± 5.4	39.8 ± 10.0
Membrane Time Constant (ms):	198 ± 42	121 ± 27