Table 5. Reported access resistance values from in vivo whole-cell patch recordings of neurons in mouse, rat and cat cortex, compared with values from the present study.

Species	Age	Ra (MΩ)	Reference
Mouse	P28-34	15–40 (17)	[20]
	P21-35	55±4 (19)	[51]
	P28-38	20–60 (12)	[52]
	5–12 weeks	30–100 (20)	[53]
	2–8 month	31±17 (21)	[54]
Mouse & Rat	P21-37 (M), P19-44 (R)	63±(99)	[55]
Rat	P21-36	47±3 (47)	[17]
	Adult	119±12 (10)	[17]
	P28-36	10–75 (48)	[56]
	P17-24	83+90 (62)	[57]
	P17-24	60 (16)	[58]
	3 months	25–60 (21)	[59]
	P19-26	20±21 (122)	[60]
	Adult	35±19 (86)	This study
Cat	Adult	50–200 (25)	[10]
	Adult	100–250 (37)	[61]
	Adult	22±15 (109)†	[36]
	Adult	140±44 (12)††	[34]
	Adult	70.5±39.7 (40)	[62]
	Adult	36±19 (83)	This study

Note the general tendency for smaller access resistances from recordings on younger animals.

^†: Recordings limited to R_a<60 MΩ.

^††: R_a taken as the mean of the reported values for the “electrode resistance” corrected with the “residual access resistance” (see table 1 in [34]).