Space Radiation Biology for “Living in Space”

Table 1

Summary of brain cellular response to HZE irradiation (doses of less than 2 Gy).

Cells	Response	Irradiation	Dose rate (Gy/min)	Time after IR	Ref.
Neuron	Cell death	^56Fe: 1.5 Gy	0.88	1 m	[141]
		^56Fe: 1.6 Gy	1	12 m	[142]
	Deficits to proliferation and differentiation	^28Si: 0.2, 1 Gy	1	24 h, 3 m	[143]
		^56Fe: 0.3, 1 Gy	0.01–1	48 h, 1 m	[144]
	Changes to dendritic, axonal, and synaptic properties	GCR (H+He+O): 0.5 Gy	0.0616	100+ d	[145]
		^16O, ^48Ti: 0.05, 0.3 Gy	0.05, 0.25	15 w	[146]
		^1H: 1 Gy	0.55	3 m	[147]
		^16O, ^28Si, ^4He: 0.3 Gy		6 w	[148]
		^56Fe: 0.5 Gy		3 m	[149]
		^1H: 0.5 Gy + ^16O: 0.1 Gy	^1H: 0.18–0.19; ^16O: 0.18–0.33	3 m	[150]
Glia	Astrocyte activation	^56Fe: 1.6 Gy	1	12 m	[142]
	Microglial activation	GCR (H+He+O): 0.5 Gy	0.0616	100+ d	[145]
		^16O, ^48Ti: 0.05, 0.3 Gy	0.05, 0.25	15 w,; 27 w	[146]
		^4He: 0.05, 0.3 Gy	0.05	12 m	[151]

h: hours; d: days; w: weeks; m: months.