Postnatal loss of Merkel cells, but not of slowly adapting mechanoreceptors in mice lacking the neurotrophin receptor p75

European Journal of Neuroscience - Tập 11 Số 11 - Trang 3963-3969 - 1999
Ilka Kinkelin1, Cheryl L. Stucky, Martin Koltzenburg
1Department of Neurology, University of Würzburg, Josef-Schneider- Str. 11, D-97080 Würzburg, Germany.

Tóm tắt

AbstractMerkel cells are specialized epidermal cells which are abundantly found in touch‐sensitive areas and which are innervated by slowly adapting mechanosensitive afferent fibres with large myelinated (Aβ) axons. The role of Merkel cells in mechanosensation, their developmental regulation and their influence on sensory neuron function are, however, incompletely understood. Here, we used mice lacking the neurotrophin receptor p75 which is expressed on Merkel cells to investigate their postnatal development and that of their innervating sensory neurons. Using morphological studies we now show that Merkel cells develop normally in both hairy and glabrous skin in these animals until 2 weeks old, but are progressively lost thereafter and have almost completely disappeared 2 months after birth. Using standard extracellular electrophysiological recording techniques we find that despite the profound loss of Merkel cells there is no corresponding reduction in the number of myelinated slowly adapting afferent fibres. Moreover, the mean mechanical threshold of these neurons and their average stimulus response function to suprathreshold mechanical stimuli does not change during the time period when more than 99% of Merkel cells are lost. We conclude that Merkel cells require p75 during the late postnatal development. However, neither the survival nor the mechanical sensitivity of slowly adapting mechanoreceptive Aβ‐fibres depends on the presence of Merkel cells.

Từ khóa


Tài liệu tham khảo

10.1016/S0896-6273(00)80047-1

10.1083/jcb.134.2.487

10.1046/j.1523-1747.1998.00277.x

Burgess P.R., 1973, Handbook of Sensory Physiology., 29

10.1038/242

10.1016/S0896-6273(00)80259-7

10.1002/neu.480251106

Dechant G., 1997, The neurotrophin receptor p75 binds neurotrophin‐3 on sympathetic neurons with high affinity and specificity, J. Neurosci., 15, 5281, 10.1523/JNEUROSCI.17-14-05281.1997

10.1002/cne.901720107

10.1002/cne.901940212

10.1002/cne.903440309

10.1016/S0896-6273(00)80240-8

10.1038/326603a0

10.1016/0165-0270(90)90155-9

10.1523/JNEUROSCI.19-14-06058.1999

10.1006/dbio.1997.8658

Fukuda J., 1996, Protective effects of neurotrophins from apoptosis of Merkel cells in monolayer culture, Soc. Neurosci. Abstract., 22, 998

10.1111/1523-1747.ep12362877

10.1007/978-3-662-00989-5_30

Ibanez C.F., 1993, Neurotrophin‐4 is a target‐derived neurotrophic factor for neurons of the trigeminal ganglion, Development, 117, 1345, 10.1242/dev.117.4.1345

10.1007/978-1-4615-8699-9_14

10.1146/annurev.ne.05.030182.000245

10.1113/jphysiol.1969.sp008721

10.1113/jphysiol.1994.sp020292

Koltzenburg M., 1997, Receptive properties of mouse sensory neurons innervating hairy skin, J. Neurophysiol., 18, 1841, 10.1152/jn.1997.78.4.1841

Koschorke G.M., 1991, Ectopic excitability of injured nerves in monkey: entertained responses to vibratory stimuli, J. Neurophysiol., 65, 693, 10.1152/jn.1991.65.3.693

10.1016/0092-8674(92)90286-L

10.1111/j.1749-6632.1961.tb35556.x

10.1007/BF02933819

10.1007/BF01181555

10.1002/ar.1092320415

10.1111/1523-1747.ep12497861

10.1016/0923-1811(91)90030-2

10.1016/0306-4522(84)90041-1

10.1016/0306-4522(84)90249-5

10.1111/1523-1747.ep12495677

10.1111/1523-1747.ep12484847

10.1016/0896-6273(92)90183-E

10.1016/0304-3940(96)12906-2

10.1002/cne.901310406

Stucky C.L., 1997, The low affinity neurotrophin receptor p75 regulates the function but not the selective survival of specific subpopulations of sensory neurons, J. Neurosci., 17, 4398, 10.1523/JNEUROSCI.17-11-04398.1997

10.1523/JNEUROSCI.18-17-07040.1998

Zelená J., 1994, Nerves and Mechanoreceptors: the Role of Innervation in the Development and Maintenance of Mammalian Mechanoreceptors