Number in Neuroscience

This is some numbers I collected long time ago.

What	How Much	Where
Constants and Equations	(a list)	go to
Brain Facts	(a list)	go to
Metabolic Energy	(a list)	go to


Number of neurons and synapses
neurons	10¹¹
synapses	10¹⁴
pyramidal neurons	>80%	Attwell and Laughlin 2001
glutamate synapses	>90%	Attwell and Laughlin 2001
ganglion cells in human regina	1.5 million	de Gelder, et al, Out of Mind, chapter 1
ganglion cells in human regina projected to LGN	90% of 1.5M	de Gelder, et al, Out of Mind, chapter 1
ganglion cells in human regina projected to superior colliculus	10⁵	de Gelder, et al, Out of Mind, chapter 1


Energy
Energy of one ATP molecule	25kT	ref
Energy of 1 mol ATP molecules (at normal cellular condition, ATP = 10mM, ADP = 0.1mM, Pi = 10mM)	53327 J 20kT	homework in integrative neuroscience I, by Paul Pfaffinger
Energy taken up by male adult per day	10^7 J	ref original ref
% Oxygen consumption of brain to total	20%	go to
% energy consumed to pumps Na and K, to total brain energy usage	50%	ref
ATP concentration at normal cellular conditions	10 mM	homework in integrative neuroscience I, by Paul Pfaffinger
ADP	0.1 mM
Pi	10 mM
Phosphate bond energy at Standard Condition	7.3kcal/mol 30.5kJ/mol 5.1*10^(-20)J/bond 11.8 kT	go to


Number
# of calcium ions flow into cell during an AP	200-13000/active zone/spike	Borst and Sakmann, 1996
# of neurotransmitter in a vesicle	4000	Kandel
# of vesicles in presynaptic bouton	1-10 CNS
diameter of a vesicle	50nm and 70-200nm
PH w/i a vesicle	5.5
PH cytoplasm	7
# of vesicle released per synaptic transmission	1	Levy and Baxter 2002
# of ions transported by a single acetylcholine-activated channel in one second	10^7
# of ions transported by Na/K pump per second	10^3









Information
information rate of fully light-adapted photo-receptor cell under random stimuli	1000 bit/s	ref
information rate of LMC	1600 bit/s	ref
synapse between photo-receptor and LMC	55 bit/s	ref
energy per bit of photo-receptor	7*10^6 ATP/bit	ref
energy per bit of LMC	0.9-3*10^6 ATP/bit	ref
energy per bit of chemical synapse	2-6*10^4 ATP/bit	ref

Other
Biological Membrane Capacitance	1uF/cm²	go to
Number of Neurons in brain	10^11
Number of Synapses in cerebral cortex	60-240trillion	Brain facts


probability to release a vesicle if action potential arrives presynaptically	0.1-0.5	go to Laughlin and Sejnowski, 2003