Main references (data with "?" refer to a reasonable guess; with
"??" to a total guess):
Number and connectivity: Patton and McNaughton,
1995; Tamamaki and Nojyo, 1995; Amaral et al., 1990.
Type: "Black box" excitatory units (glutamate)
Number: 200,000
Notes: EC output to DG and CA3 mainly comes from layer II, while the input from CA1 arrives into the deep layers (III-VI) (Freund and Buzsaki, 1996).
Connectivity:
Output (number of cells contacted, with one synapse unless specified;
in parenthesis: number of cells of that type):
34,000 DG gc (1,000,000)
100 DG bc (10,000)
10 DG cc (1000)
24 DG mc (30,000)
30 DG gpc (15,000)
100? DG mopp (10,000)
?? CA3 pc (200,000)
?? CA3 cc (1000)
?? CA3 ri (4000)
Input:
Glu ?? CA1 pc (300,000)