Table 24.

Calculated convergence of interneurons onto a CA1 pyramidal cell by layer and dendrite type, in terms of number of synapses received. For some interneuron types, no data were available but the likely locations of their synapses are marked with an asterisk. Other interneuron types are not shown in this table. The ’Total Available’ column values are based on the synapse counts on an average CA1 pyramidal cell from Megias et al. (2001). The ’Total Claimed’ column gives the counts for the presynaptic cell types we have calculated in this assessment, and the ’Total Remaining’ column gives the number of synapses remaining on the average pyramidal cell after subtracting the estimated innervation calculated in this assessment.

Cell Type	Oriens		Radiatum			LM	Soma	Axon	Total Boutons
	Distal	Proximal	Thick prox.	Thick dist.	Thin
Ivy	169	4	4		211	34			422
Neurogliaform					24	116			140
O-LM	5					72			77
Double proj.	8				6				14
Oriens retrohipp.	7				5				12
PV+ basket		61	61				61		183
Bistratified	53	3	4		44				104
Axo-axonic								34	34
CCK+ basket		37	37			1	31		106
SCA	1	0	0		12	1			14
PPA						12			12
Synapse Summary
Total Available	405	233	193	111	437	335	92	34	1,840
Total Claimed	243	105	106	0	302	236	92	34	1,118
Total Remaining	162	128	87	111	135	99	0	0	722
Percent Remaining	40%	55%	45%	100%	31%	30%	0%	0%	39%