The action of 5-Methoxytryptophol (5ML) on certain thalamic and hypothalamic nuclei in the jerboas depends on seasons Nezha BOUHADDOU

Transcription

1 The action of 5-Methoxytryptophol (5ML) on certain thalamic and hypothalamic nuclei in the jerboas depends on seasons Nezha BOUHADDOU Group of research on biological rhythms University Mohamed V Agdal - Rabat MOROCCO October 28

2 Tryptophan Serotonin NAT N-acetyl serotonin HIOMT Melatonin

3 Tryptophan Serotonin NAT HIOMT 5-Methoxytryptophol (5ML) N-acetyl serotonin HIOMT Melatonin

4 5ML rhythms 14 Concentrations Concentration du 5-ML of 5ML dans in the les pineal glandes / pinéales seasons en fonction des saisons ML (pg/glande) may august September october november mai août septembre octobre novembre Mois Lakhdar-Ghazal Nouria, 1992

5 5ML action on the reproductive cycle 4,5 LP 5ML 4 CONT 3,5 3 2,5 2 1,5 1 volume Testicular testiculaire volume (cm³) (cm3),5 mois 27/5/23 3/6/23 1/6/23 17/6/23 24/6/23 1/7/23 8/7/23 15/7/23 22/7/23 29/7/23 5/8/23 12/8/23 19/8/23 26/8/23 2/9/23 9/9/23 16/9/23 23/9/23 3/9/23 Spring Jamal Chakir, 21

6 OBJECTIVE - The 5ML act on thalamic and hypothalamic nuclei - that it s action is season/photoperiod dependent.

7 Material and Methods 2 jerboas, females, adults, natural photoperiod Autumn Winter Spring Summer 3-5ML 2-Vehicle 3-5ML 2-Vehicle 3-5ML 2-Vehicle 3-5ML 2-Vehicle Sun rise (h = h) Injections (h 1 = h + 2h) Perfusion (h 2 = h + 3h3) - C Fos Immunocytochemistry on floating sections

8 RESULTS moyenne des cellules Mean of Immunoreactive cells immunoréactives immunoréactivité C-Fos Immunoreactivity au c-fos au in niveau the whole du SCN SCNglobal *** * autumn automne winter hiver printemps spring summer été seasons saison 5ML VEHICLE Mean of Immunoreactive cells nombre de cellules exprimant le c-fos Sensible Cells to 5ML in the global SCN nombre de cellules sensibles au 5ML dans le SCN global spring summer autumn winter immunoreactive cells to 5ML

9 RESULTS moyenne des cellules Mean of Immunoreactive cells immunoréactives immunoréactivité C-Fos Immunoreactivity au c-fos au in niveau the whole du SCN SCNglobal *** * autumn automne winter hiver printemps spring summer été seasons saison 5ML VEHICLE Mean of Immunoreactive cells nombre de cellules exprimant le c-fos Sensible Cells to 5ML in the global SCN nombre de cellules sensibles au 5ML dans le SCN global spring summer autumn winter immunoreactive cells to 5ML 5-ML (pg/glande) Concentrations du 5-ML dans les glandes pinéales en Concentration of 5ML in the pineal gland / fonction des saisons seasons may mai august août September septembre october octobre november novembre Mois

10 RESULTS moyenne des cellules immunoréactives Mean Mean of of Immunoreactive Immunoreactive cells cells Mean of Immunoreactive cells immunoréactivité C-Fos Immunoreactivity au c-fos au in niveau the whole du PVT PVT+Hb global * * automne hiver printemps été saison ** ** autumn winter spring summer seasons Sensible Cells Cells to to 5ML 5ML in in the the global PVT+Hb SCN spring summer autumn winter 5ML immunoreactive cells to 5ML VEHICLE - Probable implication of the PVT in the control of certain rhythmic functions by modulating the cells activity.

11 CONCLUSIONS - The 5ML is involved in the photoperiodic control of seasonal reproduction. - It act on the SCN and PVT dependently of seasons/photoperiod - It s action on the SCN and PVT suggest that it implies this 2 structures in the control of seasonal reproduction.

12 Thank you

13 Jerboas are : - Jaculus orientalis - family Dipodidae - Asia and northern Africa - Nocturnal jumping desert rodents - Resembles mice with a long tufted tail and very long hind legs - Photoperiodic animal

14 Seasonal rhythms Melatonin PG Sympathic fibers SCN retina Superior cervical ganglion Bittman, 1984

15 Summery - Results of the present study demenstrate that: - 5ML selectively activates the SCN during autumn and winter. This results suggest that 5ML

16 PROSPECTS 1. To confirm these preliminary results and to characterize the nature of the cells in which the 5ML induces c-fos and translates the photoperiod by double labelling with the VIP. 2. To confirm its modulating effect on the principal clock of the SCN by showing its induction in the VP cells. 3. To determine the cells where the 5ML induces c-fos in the PVT and the lateral habenula. 4. To undertake the study of its modulation effect on the expression of the clock genes, which control the circadian and seasonal rhythmicity.

17 PC PL Jamal Chakir, 21 VT VT moyen moyen en en cm cm 3 3 4/8/1999 4/8/1999 4/9/1999 4/9/1999 4/1/1999 4/1/1999 4/11/1999 4/11/1999 4/12/1999 4/12/1999 4/1/2 4/1/2 4/2/2 4/2/2 4/3/2 4/3/2 4/4/2 4/4/2 4/5/2 4/5/2 4/6/2 4/6/2 4/7/2 4/7/2 4/8/2 4/8/2 4/9/2 4/9/2 4/1/2 4/1/2 4/11/2 4/11/2 4/12/2 4/12/2 4/1/21 4/1/21 4/2/21 4/2/21 4/3/21 4/3/ Reproduction activation Quiescence sexuelle Photoréfraction Hibernation activation

18 175 Melatonin concentrations in pineals in spring 175 Melatonin in pineals in autumn 175 Melatonin concentrations in pineals in winter Mel (pg/gland) Mel (pg/gland) Mel (pg/gland) Hours Hours 1 Printemps 1 Automne 1 Hiver ML (pg/glande) ML (pg/glande) ML (pg/glande) L /8.3 D 12. L /12. D 8.3 L /15.3 D Lakhdar-Ghazal Nouria, 1992

19 Autumn Summer Vehicle Vehicle PVT PVT 5ML D 5ML PVT PVT

20 H5ML HMEL HVHL 15 1 A5ML AMEL AVHL moyenne moyenne