TABLE 1.

Neuronal losses in neurotrophin and Trk-deficient mice^a

Determinant	TrkA	NGF	TrkB	BDNFb	NT-4/5c	TrkC	NT-3	TrkB/TrkCd	NT-3/BDNF	NT4/BDNFe	NT-3/BDNF/NT-4/5f	p75NTRg
Sensory ganglia
Trigeminal	70%	75%	60%	30%	NS	21%	60%	ND	74%	9%	88%	ND
N-P	ND	ND	90%	45%	40%	14%	30%	ND	62%	90%	96%	ND
Vestibular	NS	ND	60%	85%	NS	15%	20%	100%	100%	89%	100%	ND
Cochlear	NS	NS	15%	7%	ND	50%	85%	65%	100%	ND	ND	ND
Dorsal root	70–90%	70%	30%	35%	NS	20%	60%	41%	83%	NS	92%	Small
Geniculate	ND	ND	ND	ND	ND	11%	35%	ND	ND	ND	100%	ND
TMNh	ND	ND	38%	41%	8%	45%	57%	ND	88%	46%	95%	ND
Comments	—i	—i		—j	—k	—l	—m					—n
Sympathetic ganglia
Superior cervical	>95%	>95%	ND	ND	NS	NS	50%		ND	ND	47%	NS
Motor
Facial	ND	ND	ND	NS	ND					NS	22%	ND
Spinal cord	ND	ND	NS	NS	NS	ND	ND	ND	ND	NS	20%	ND
CNS	—o		ND	—p	ND	ND	—q	—r				—s
Viability	P	P	VP	PM	G	M	VP	VP	VP		VP	G

^aNote: Neuronal losses are expressed as the percentage of neurons lost in the mutants compared with the wild-type controls. This table is updated from a similar table in Reichardt & Fariñas (1997), in which original references for older papers is provided. N-P, Nodose-petrosal; TMN, Trigeminal mesencephalic nucleus neurons; ND, not done; NS, not significant; P, poor; VP, very poor; PM, poor to moderate; M, moderate; G, good.

^bBrady et al 1999.

^cStucky et al 1998.

^dMinichiello et al 1996.

^eLiebl et al 2000.

^fLin & Jaenisch 2000.

^gFundin et al 1997.

^hFan et al 2000.

ⁱSmall CGRP (nociceptive) and BS1 (thermoceptive) positive neurons missing.

^jMyelinated and nonmyelinated axon lost. Ia afferents present. Complete loss of nodose-petrosal innervation of carotid body.

^kD-hair afferents completely lost.

^lProprioceptive neurons missing.

^mProprioceptive and cutaneous mechano-receptors missing. Partial losses of nociceptors. Partial losses of D-hair and SA fibers.

ⁿPartial deficits in all neurons.

^oCholinergic basal forebrain neurons present. Reduced hippocampal innervation.

^pDeficits in NPY, calbindin, and parvalbumin expression. Cerebellar foliation defect.

^qNo clear deficits.

^rIncreased apoptosis in hippocampal and cerebellar granule neurons.

^sIncrease in the number of forebrain cholinergic neurons.