- Email: [email protected]
35. Early rearing & genotypic influences on CNS serotonin & behavior in nonhuman primates
10S
BIOL PSYCHIATRY 2000;47:1S–173S
only beginning to emanate. Integration of well-advanced strategies of complex genetics including behavioral traits and techniques that alter or inactivate gene expression (constitutive or regulated gene knockout), will eventually elucidate the status of the 5HTT in development of personality and modification of behavior. It will also will also bring light to the 5HTT’s role in the pathogenesis and treatment response of affective and neurodegenerative spectrum disorders as well as of substance abuse.
Thursday Abstracts
34. SEROTONIN TRANSPORTER GENOTYPES, CSF 5HIAA, AND CARDIOVASCULAR REACTIVITY TO STRESS R.B. Williams, J.C. Barefoot, G. Clary, K.M. Gadde, K. Grichnik, M.J. Helms, C.M. Kuhn, D.A. Marchuk, S.M. Schanberg, I.C. Siegler, M. Stafford-Smith, E.C. Suarez, I.K. Svenson Departments of Psychiatry and Behavioral Sciences, Pharmacology, Anesthesiology and Genetics, Duke University Medical Center, Durham, NC 27710
33. DOPAMINE D4 RECEPTOR, SEROTONIN TRANSPORTER GENOTYPES AND TEMPERAMENT IN EARLY CHILDHOOD R.P. Ebstein (1) and J. Auerbach (2) (1) Research Laboratory, S. Herzog Memorial Hospital, Jerusalem, Israel (2) Department of Behavioral Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel We have initiated a longitudinal study of early childhood behavior starting at two-weeks of age. Initially, the behavioral effects of two common polymorphisms linked respectively in some, but not all, studies to Novelty Seeking (dopamine D4 receptor exon III repeat region, DRD4) and neuroticism and harm avoidance (serotonin transporter promoter region, 5-HTTLPR) were examined in a group of 81 two-week old neonates. Neonate temperament was evaluated using the Brazelton neonatal assessment scale (NBAS). Multivariate tests of significance showed a significant association of D4DR across four behavioral clusters pertinent to temperament including Orientation, Motor Organization, Range of State and Regulation of State. A significant multivariate interaction was also observed between DRD4 and 5-HTTLPR. The effect of the homozygous short 5-HTTLPR genotype (s/s) was to lower the Orientation score for the group of neonates lacking the long form of DRD4. These children have also been evaluated at 2 months using Rothbart s Infant Behavior Questionnaire (IBQ). There were significant negative correlations between neonatal Orientation and Motor Organization (NBAS) at 2 weeks and Negative Emotionality, especially distress in daily situations, at 2 months. There were significant main effects for Negative Emotionality and distress when the infants were grouped by both polymorphisms. Infants with long DRD4 alleles had significantly lower scores on Negative Emotionality (F[1,72] ⫽ 8.50, P ⫽ 0.005) and Distress to Limitations (F[1,72] ⫽ 4.93, P ⫽ 0.03) than infants with short DRD4 alleles. In contrast, infants with the short homozygous (s/s) 5-HTTLPR genotype had higher scores on Negative Emotionality (F[1,72] ⫽ 3.88, P ⫽ 0.053) and Distress to Limitations (F[1,72] ⫽ 4.94, P ⫽ 0.029) than infants with the long (l)/s or l/l genotypes. The strongest effects occurred in those infants with the s/s 5-HTTLPR polymorphism who also were lacking long DRD4 alleles which in some studies has been linked to adult novelty seeking. These infants showed most Negative Emotionality and most distress to daily situations, temperament traits that are perhaps the underpinning of adult neuroticism.
We have hypothesized that altered CNS serotonin function is an important mediator of the observed clustering of psychosocial risk factors and accompanying health-damaging biobehavioral characteristics in certain individuals and groups. We are testing this hypothesis by determining associations among CSF 5HIAA (a measure of CNS serotonin turnover), Genotype (1 vs s alleles) of a functional polymorphism of the promoter region of the serotonin transporter gene (5HTTLPR, described by Lesch et al., 1996), and a range of psychosocial and biobehavioral characteristics. In this ongoing project, 60 subjects (66% male, 52% white, aged 18 – 49) have completed a 3 day Clinical Research Center inpatient protocol that collects data in the areas described above. Results thus far include a significant (P ⫽ 0.007) association between 5HTTLPR genotypes and CSF 5HIAA levels: l/l ⫽ 21.6 ng/ml (1.6 SEM); l/s ⫽ 22.9 (2.0); s/s ⫽ 15.1 (2.4). Subjects were randomized to either tryptophan depletion or infusion, with a sham treatment the first day followed by active depletion or infusion the second day. In the tryptophan depletion arm subjects with l/l or l/s genotype showed larger MAP and HR responses (P ⬍ 0.004) to a mental challenge protocol on both sham and active depletion days. A similar high reactivity pattern was found among high 5HIAA subjects on the sham day, with attenuation on the active day. In the infusion arm, there were no 5HIAA effects and 5HTTLPR genotype was associated only with a higher MAP in subjects with l/l or l/s genotype during rest and challenge periods on both sham and active days. To our knowledge, this is the first observation of an association between a particular genotype (5HTTLPR, acting as an autosomal dominant) and an index of CNS serotonin turnover. Findings also suggest that CNS serotonin function—whether indexed by 5HIAA or 5HTTLPR genotype—is involved in regulation of cardiovascular responses to stress. We anticipate that other findings, related to neuroendocrine and immune parameters, will be available by the time of the meeting.
35. EARLY REARING & GENOTYPIC INFLUENCES ON CNS SEROTONIN & BEHAVIOR IN NONHUMAN PRIMATES J.D. Higley (1), A.J. Bennett (1), A. Heils (2), J. Long (3), J. Lorenz (3), M. Champoux (4), S.J. Suomi (4), K.P. Lesch (2) (1) Laboratory of Clinical Studies, Primate Unit, NIAAA, NIH, Poolesville, MD, 20837 (2) Department of Psychiatry and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (3) Laboratory of Neurogenetics, NIAAA, NIH, Rockville, MD, 20852 (4) Laboratory of Comparative Ethology, NICHD, NIH, Poolesville, MD, 20837 Length variation in the serotonin transporter gene-linked promoter region (5-HTTLPR), first described by Lesch et al., are related to serotonin
Thursday Abstracts
functioning, serotonin-related behaviors, and psychopathological disorders. A similar polymorphism, believed to be homologous, also exists in nonhuman primates. We have recently analyzed the relationship between the rhesus macaque serotonin transporter (rh5-HTTLPR) genotypes, CSF 5-HIAA concentrations, and aggression. Our results show that rhesus macaques with the short rh5-HTTLPR allele have low CSF 5-HIAA concentrations, and are highly aggressive. However, the phenotypic expression of this short allele is environmentally-dependent, with the short allele associated with low CSF 5-HIAA concentrations only in subjects reared in age-matched peer groups that lack adult influence. Aggression was shown to be higher in subjects with the short allele than in subjects with the long allele regardless of early rearing experiences. In humans, the 5-HTTLPR is associated with early infant temperament. Similar data for neonatal rhesus monkeys were collected during assessments on days of life 7, 14, 21 and 30. Subjects with the short rh5-HTTLPR variant exhibit diminished orientation, attention, and increased emotional responses. Consistent with our earlier findings, these differences were generally exaggerated by parental deprivation. These findings illustrate the interacting influence of genotype and early rearing experiences on the developing phenotype.
BIOL PSYCHIATRY 2000;47:1S–173S
11S
sexual dysfunction was observed in patients receiving MK-0869 (3%) or placebo (4%) compared with paroxetine (26%) [p ⬍ 0.001]. Results indicate MK-0869 in this study was an effective, well-tolerated antidepressant with potential anxiolytic activity, and support a role for SP acting at the NK1 receptor in the pathophysiology of depression and perhaps anxiety. As available, data from additional studies may be presented and discussed.
37. REDUCED EXPRESSION OF PKC ISOZYMES IN THE BRAINS OF TEENAGE SUICIDE VICTIMS G.N. Pandey, Y. Dwivedi, H. Rizavi, R. Roberts, R.C. Conley, C. Tamminga The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612
PAPER SESSIONS Affective Disorders I/Schizophrenia I Thursday, May 11, 2:30 PM–5:00 PM Location: Water Tower Chair: S. Charles Schulz
36. CLINICAL PROFILE OF SUBSTANCE P ANTAGONISTS M.S. Kramer (1), N.R. Cutler (2), J. Feighner (3), R. Shrivastava (4), J.S. Carman (5), G. Liu (1), D. Snavely (1), E. Wyatt-Knowles (1), S.A. Reines (1), N.M. Rupniak (6) (1) USA; Merck Laboratories, West Point, PA, (2) California Clinical Trials, Beverly Hills, CA, (3) Feighner Research Institute, San Diego, CA, (4) Eastside Medical Group, New York, NY, (5) Carman Research, Smyrna, GA, (6) Merck Laboratories, Terlings Park, UK Based on limbic co-localization of tachykinins (i.e. Substance P; [SP]) with monoamines, and behavioral pharmacology data, we postulated that the selective NK1 antagonist, MK-0869, would be antidepressant or anxiolytic in patients with major depressive disorder. Outpatients (N ⫽ 213) at four investigative sites, scoring ⱖ 22 on the 17-item Hamilton Depression Scale (HAM-D) score and ⱖ 15 on the total Hamilton Anxiety Scale, were randomized to 6 weeks double-blind treatment with MK-0869 300 mg/day, paroxetine HCI 20 mg/day, or placebo. Clinically relevant antidepressant efficacy was observed in patients receiving MK-0869 or paroxetine. Antidepressant effect of MK-0869 (scored on the HAM-D, the predefined primary outcome measure) was observed by week 1, and increased over timecourse of the study. Mean change from baseline to week 6 for MK-0869 (⫺13.6 points), or paroxetine (⫺12.8 points), was greater (p ⫽ 0.003 and p ⫽ 0.010, respectively) than placebo (⫺9.3 points). Results were consistent. Robust anxiolytic effects were also observed with MK-0869, which was welltolerated. Numerically, more patients receiving paroxetine (19%) discontinued (mostly for nausea) for clinical adverse experiences compared with MK-0869 (9%) or placebo (9%). Strikingly lower incidence of
We have recently reported that the binding of [3H]Phorbol dibutyrate to protein kinase C (PKC), which is an important component of the phosphoinositide (PI) signaling system, is significantly reduced in Broadmann’s Areas (BA) 8/9 of teenage suicide victims. We have now determined PKC activity; and protein and mRNA expression of PKC isozymes by immunolabeling and quantitative RT-PCR, respectively, in BA 8/9 and hippocampus of teenage suicide victims and matched control subjects. Postmortem brain samples were obtained from the brain collection program of the Maryland Psychiatric Research Center and the diagnosis was made by DSM-IV and diagnostic evaluation after death (DEAD) instruments. We found that PKC activity was significantly lower in BA 8/9 and hippocampus in suicide victims as compared with the control subjects. We also observed that the immunolabeling of PKC␣, , and ␥ isozymes was significantly decreased in both the brain areas of the suicide victims. To examine if the a decrease in protein expression of PKC isozymes is associated with decreased mRNA level, we are currently determining mRNA levels of PKC isozymes using RT-PCR method and so far have observed that the PKC␣ mRNA expression is significantly decreased in BA 8/9 of suicide victims. Further results are awaited. Our results suggest that the reduction in PKC recognition sites in BA 8/9 of teenage suicide victims is associated with decreased PKC activity as well as the immunolabeling of PKC␣, , and ␥ isozymes, and further suggests that teenage suicide may be associated with an impaired PI signaling system. Support: R01 MH 48153-04
38. MOTOR PROGRAMMING DEFICITS IN DEPRESSION: SUPPORT FOR A DOPAMINERGIC MECHANISM M.P. Caligiuri, B. Vukov, J.C. Gillin Department of Psychiatry, University of California, San Diego and the San Diego VA Healthcare System Several investigators have reported parallels between motor and cognitive slowing in patients with major depression (MD). Such a relationship between depression and motor function suggests the possibility of a shared neuropathologic mechanism. This mechanism has remained elusive largely because depression may involve any of several neurotransmitters. While others have shown that MD and parkinsonism share a number of features, especially in the motor domain, previous technologies have not delineated the cognitive from neuromotor aspects of the motor impairment in MD. The aim of the present study was to examine motor programming in MD patients
BIOL PSYCHIATRY 2000;47:1S–173S
only beginning to emanate. Integration of well-advanced strategies of complex genetics including behavioral traits and techniques that alter or inactivate gene expression (constitutive or regulated gene knockout), will eventually elucidate the status of the 5HTT in development of personality and modification of behavior. It will also will also bring light to the 5HTT’s role in the pathogenesis and treatment response of affective and neurodegenerative spectrum disorders as well as of substance abuse.
Thursday Abstracts
34. SEROTONIN TRANSPORTER GENOTYPES, CSF 5HIAA, AND CARDIOVASCULAR REACTIVITY TO STRESS R.B. Williams, J.C. Barefoot, G. Clary, K.M. Gadde, K. Grichnik, M.J. Helms, C.M. Kuhn, D.A. Marchuk, S.M. Schanberg, I.C. Siegler, M. Stafford-Smith, E.C. Suarez, I.K. Svenson Departments of Psychiatry and Behavioral Sciences, Pharmacology, Anesthesiology and Genetics, Duke University Medical Center, Durham, NC 27710
33. DOPAMINE D4 RECEPTOR, SEROTONIN TRANSPORTER GENOTYPES AND TEMPERAMENT IN EARLY CHILDHOOD R.P. Ebstein (1) and J. Auerbach (2) (1) Research Laboratory, S. Herzog Memorial Hospital, Jerusalem, Israel (2) Department of Behavioral Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel We have initiated a longitudinal study of early childhood behavior starting at two-weeks of age. Initially, the behavioral effects of two common polymorphisms linked respectively in some, but not all, studies to Novelty Seeking (dopamine D4 receptor exon III repeat region, DRD4) and neuroticism and harm avoidance (serotonin transporter promoter region, 5-HTTLPR) were examined in a group of 81 two-week old neonates. Neonate temperament was evaluated using the Brazelton neonatal assessment scale (NBAS). Multivariate tests of significance showed a significant association of D4DR across four behavioral clusters pertinent to temperament including Orientation, Motor Organization, Range of State and Regulation of State. A significant multivariate interaction was also observed between DRD4 and 5-HTTLPR. The effect of the homozygous short 5-HTTLPR genotype (s/s) was to lower the Orientation score for the group of neonates lacking the long form of DRD4. These children have also been evaluated at 2 months using Rothbart s Infant Behavior Questionnaire (IBQ). There were significant negative correlations between neonatal Orientation and Motor Organization (NBAS) at 2 weeks and Negative Emotionality, especially distress in daily situations, at 2 months. There were significant main effects for Negative Emotionality and distress when the infants were grouped by both polymorphisms. Infants with long DRD4 alleles had significantly lower scores on Negative Emotionality (F[1,72] ⫽ 8.50, P ⫽ 0.005) and Distress to Limitations (F[1,72] ⫽ 4.93, P ⫽ 0.03) than infants with short DRD4 alleles. In contrast, infants with the short homozygous (s/s) 5-HTTLPR genotype had higher scores on Negative Emotionality (F[1,72] ⫽ 3.88, P ⫽ 0.053) and Distress to Limitations (F[1,72] ⫽ 4.94, P ⫽ 0.029) than infants with the long (l)/s or l/l genotypes. The strongest effects occurred in those infants with the s/s 5-HTTLPR polymorphism who also were lacking long DRD4 alleles which in some studies has been linked to adult novelty seeking. These infants showed most Negative Emotionality and most distress to daily situations, temperament traits that are perhaps the underpinning of adult neuroticism.
We have hypothesized that altered CNS serotonin function is an important mediator of the observed clustering of psychosocial risk factors and accompanying health-damaging biobehavioral characteristics in certain individuals and groups. We are testing this hypothesis by determining associations among CSF 5HIAA (a measure of CNS serotonin turnover), Genotype (1 vs s alleles) of a functional polymorphism of the promoter region of the serotonin transporter gene (5HTTLPR, described by Lesch et al., 1996), and a range of psychosocial and biobehavioral characteristics. In this ongoing project, 60 subjects (66% male, 52% white, aged 18 – 49) have completed a 3 day Clinical Research Center inpatient protocol that collects data in the areas described above. Results thus far include a significant (P ⫽ 0.007) association between 5HTTLPR genotypes and CSF 5HIAA levels: l/l ⫽ 21.6 ng/ml (1.6 SEM); l/s ⫽ 22.9 (2.0); s/s ⫽ 15.1 (2.4). Subjects were randomized to either tryptophan depletion or infusion, with a sham treatment the first day followed by active depletion or infusion the second day. In the tryptophan depletion arm subjects with l/l or l/s genotype showed larger MAP and HR responses (P ⬍ 0.004) to a mental challenge protocol on both sham and active depletion days. A similar high reactivity pattern was found among high 5HIAA subjects on the sham day, with attenuation on the active day. In the infusion arm, there were no 5HIAA effects and 5HTTLPR genotype was associated only with a higher MAP in subjects with l/l or l/s genotype during rest and challenge periods on both sham and active days. To our knowledge, this is the first observation of an association between a particular genotype (5HTTLPR, acting as an autosomal dominant) and an index of CNS serotonin turnover. Findings also suggest that CNS serotonin function—whether indexed by 5HIAA or 5HTTLPR genotype—is involved in regulation of cardiovascular responses to stress. We anticipate that other findings, related to neuroendocrine and immune parameters, will be available by the time of the meeting.
35. EARLY REARING & GENOTYPIC INFLUENCES ON CNS SEROTONIN & BEHAVIOR IN NONHUMAN PRIMATES J.D. Higley (1), A.J. Bennett (1), A. Heils (2), J. Long (3), J. Lorenz (3), M. Champoux (4), S.J. Suomi (4), K.P. Lesch (2) (1) Laboratory of Clinical Studies, Primate Unit, NIAAA, NIH, Poolesville, MD, 20837 (2) Department of Psychiatry and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (3) Laboratory of Neurogenetics, NIAAA, NIH, Rockville, MD, 20852 (4) Laboratory of Comparative Ethology, NICHD, NIH, Poolesville, MD, 20837 Length variation in the serotonin transporter gene-linked promoter region (5-HTTLPR), first described by Lesch et al., are related to serotonin
Thursday Abstracts
functioning, serotonin-related behaviors, and psychopathological disorders. A similar polymorphism, believed to be homologous, also exists in nonhuman primates. We have recently analyzed the relationship between the rhesus macaque serotonin transporter (rh5-HTTLPR) genotypes, CSF 5-HIAA concentrations, and aggression. Our results show that rhesus macaques with the short rh5-HTTLPR allele have low CSF 5-HIAA concentrations, and are highly aggressive. However, the phenotypic expression of this short allele is environmentally-dependent, with the short allele associated with low CSF 5-HIAA concentrations only in subjects reared in age-matched peer groups that lack adult influence. Aggression was shown to be higher in subjects with the short allele than in subjects with the long allele regardless of early rearing experiences. In humans, the 5-HTTLPR is associated with early infant temperament. Similar data for neonatal rhesus monkeys were collected during assessments on days of life 7, 14, 21 and 30. Subjects with the short rh5-HTTLPR variant exhibit diminished orientation, attention, and increased emotional responses. Consistent with our earlier findings, these differences were generally exaggerated by parental deprivation. These findings illustrate the interacting influence of genotype and early rearing experiences on the developing phenotype.
BIOL PSYCHIATRY 2000;47:1S–173S
11S
sexual dysfunction was observed in patients receiving MK-0869 (3%) or placebo (4%) compared with paroxetine (26%) [p ⬍ 0.001]. Results indicate MK-0869 in this study was an effective, well-tolerated antidepressant with potential anxiolytic activity, and support a role for SP acting at the NK1 receptor in the pathophysiology of depression and perhaps anxiety. As available, data from additional studies may be presented and discussed.
37. REDUCED EXPRESSION OF PKC ISOZYMES IN THE BRAINS OF TEENAGE SUICIDE VICTIMS G.N. Pandey, Y. Dwivedi, H. Rizavi, R. Roberts, R.C. Conley, C. Tamminga The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612
PAPER SESSIONS Affective Disorders I/Schizophrenia I Thursday, May 11, 2:30 PM–5:00 PM Location: Water Tower Chair: S. Charles Schulz
36. CLINICAL PROFILE OF SUBSTANCE P ANTAGONISTS M.S. Kramer (1), N.R. Cutler (2), J. Feighner (3), R. Shrivastava (4), J.S. Carman (5), G. Liu (1), D. Snavely (1), E. Wyatt-Knowles (1), S.A. Reines (1), N.M. Rupniak (6) (1) USA; Merck Laboratories, West Point, PA, (2) California Clinical Trials, Beverly Hills, CA, (3) Feighner Research Institute, San Diego, CA, (4) Eastside Medical Group, New York, NY, (5) Carman Research, Smyrna, GA, (6) Merck Laboratories, Terlings Park, UK Based on limbic co-localization of tachykinins (i.e. Substance P; [SP]) with monoamines, and behavioral pharmacology data, we postulated that the selective NK1 antagonist, MK-0869, would be antidepressant or anxiolytic in patients with major depressive disorder. Outpatients (N ⫽ 213) at four investigative sites, scoring ⱖ 22 on the 17-item Hamilton Depression Scale (HAM-D) score and ⱖ 15 on the total Hamilton Anxiety Scale, were randomized to 6 weeks double-blind treatment with MK-0869 300 mg/day, paroxetine HCI 20 mg/day, or placebo. Clinically relevant antidepressant efficacy was observed in patients receiving MK-0869 or paroxetine. Antidepressant effect of MK-0869 (scored on the HAM-D, the predefined primary outcome measure) was observed by week 1, and increased over timecourse of the study. Mean change from baseline to week 6 for MK-0869 (⫺13.6 points), or paroxetine (⫺12.8 points), was greater (p ⫽ 0.003 and p ⫽ 0.010, respectively) than placebo (⫺9.3 points). Results were consistent. Robust anxiolytic effects were also observed with MK-0869, which was welltolerated. Numerically, more patients receiving paroxetine (19%) discontinued (mostly for nausea) for clinical adverse experiences compared with MK-0869 (9%) or placebo (9%). Strikingly lower incidence of
We have recently reported that the binding of [3H]Phorbol dibutyrate to protein kinase C (PKC), which is an important component of the phosphoinositide (PI) signaling system, is significantly reduced in Broadmann’s Areas (BA) 8/9 of teenage suicide victims. We have now determined PKC activity; and protein and mRNA expression of PKC isozymes by immunolabeling and quantitative RT-PCR, respectively, in BA 8/9 and hippocampus of teenage suicide victims and matched control subjects. Postmortem brain samples were obtained from the brain collection program of the Maryland Psychiatric Research Center and the diagnosis was made by DSM-IV and diagnostic evaluation after death (DEAD) instruments. We found that PKC activity was significantly lower in BA 8/9 and hippocampus in suicide victims as compared with the control subjects. We also observed that the immunolabeling of PKC␣, , and ␥ isozymes was significantly decreased in both the brain areas of the suicide victims. To examine if the a decrease in protein expression of PKC isozymes is associated with decreased mRNA level, we are currently determining mRNA levels of PKC isozymes using RT-PCR method and so far have observed that the PKC␣ mRNA expression is significantly decreased in BA 8/9 of suicide victims. Further results are awaited. Our results suggest that the reduction in PKC recognition sites in BA 8/9 of teenage suicide victims is associated with decreased PKC activity as well as the immunolabeling of PKC␣, , and ␥ isozymes, and further suggests that teenage suicide may be associated with an impaired PI signaling system. Support: R01 MH 48153-04
38. MOTOR PROGRAMMING DEFICITS IN DEPRESSION: SUPPORT FOR A DOPAMINERGIC MECHANISM M.P. Caligiuri, B. Vukov, J.C. Gillin Department of Psychiatry, University of California, San Diego and the San Diego VA Healthcare System Several investigators have reported parallels between motor and cognitive slowing in patients with major depression (MD). Such a relationship between depression and motor function suggests the possibility of a shared neuropathologic mechanism. This mechanism has remained elusive largely because depression may involve any of several neurotransmitters. While others have shown that MD and parkinsonism share a number of features, especially in the motor domain, previous technologies have not delineated the cognitive from neuromotor aspects of the motor impairment in MD. The aim of the present study was to examine motor programming in MD patients