Table 1.

rMTF response types to BBN carrier RAN SAM stimuli

	Bandpass	Mixed	High-pass	Atypical
Young anesthetized (n = 42)	33% (n = 14)	40% (n = 17)	17% (n = 7)***	10% (n = 4)
Young awake (n = 73)	37% (n = 27)	48% (n = 35)	4% (n = 3)	11% (n = 8)
Aged awake (n = 60)	25% (n = 15)	50% (n = 30)	5% (n = 3)	20% (n = 12)*

Bandpass and mixed MGB units were major SAM response types for all three groups. Of the three groups, MGB units from young anesthetized rats showed the largest percentage of high-pass SAM response type (***p < 0.001, x₍₃₎² = 22.85, χ² test). The percentage of atypical SAM response types increased as rats became older (*p < 0.05, x₍₃₎² = 8.048; χ² test).