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Updated: Aug 18, 2026
Spinal Cord Electrophysiology
Published on: January 18, 2010
Modulation of locomotor activity by multiple 5-HT and dopaminergic receptor subtypes in the neonatal mouse spinal
M A Madriaga1, L C McPhee, T Chersa
1Department of Physiology and Biophysics, Calgary Brain Institute, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada.
Abstract:
Recently, it has been shown that bath-applied 5-HT can elicit fictive locomotion from perinatal mouse preparations. Since 5-HT acts on multiple receptor subtypes, the focus of this study was to examine which receptor families contribute to the genesis and modulation of locomotor activity. Blockade of 5-HT(2) (ketanserin or N-desmethylclozapine) or 5-HT(7) receptors (SB-269970) could reversibly block or modulate the locomotor-like pattern. A 5-HT(2) agonist (alpha-methyl-5-HT) was shown to be capable of activating the rhythm. Bath application of 5-HT(7) agonists (5-CT) generally led to a tonic increase in neurogram discharge, accompanied by bouts of rhythmic activity. Blockade of dopaminergic receptors (D(1) [R-(+)-SCH-23390 or LE 300]/D(2) [(+/-)-sulpiride or L-741,626] ) could reversibly disrupt the rhythm and most effectively did so when the D(1) and D(2) antagonists were added together. Conversely, 5-HT(2) and D(1)/D(2) agonists can interact to evoke locomotor activity. Overall, our data show that, in the neonatal mouse preparation, 5-HT evoked locomotion is partly dependent on activation of 5-HT(2), 5-HT(7), and dopaminergic receptor subtypes.
Insights
Serotonin (5-HT) evokes fictive locomotion in neonatal mice through 5-HT(2), 5-HT(7), and dopamine receptor activation. These receptors are crucial for generating and modulating locomotor activity patterns.
Area of Science:
- Neuroscience
- Developmental Biology
- Pharmacology
Background:
- Serotonin (5-HT) is known to influence motor activity.
- Perinatal mouse preparations exhibit fictive locomotion when exposed to 5-HT.
- The specific receptor subtypes involved in 5-HT-induced locomotion are not fully understood.
Purpose of the Study:
- To identify the specific serotonin (5-HT) and dopaminergic receptor subtypes mediating fictive locomotion in neonatal mice.
- To investigate the roles of 5-HT(2), 5-HT(7), and dopaminergic receptors in the genesis and modulation of locomotor activity.
Main Methods:
- Utilized perinatal mouse spinal cord preparations to study fictive locomotion.
- Employed receptor antagonists (ketanserin, N-desmethylclozapine, SB-269970, R-(+)-SCH-23390, (+/-)-sulpiride, L-741,626) to block specific receptor subtypes.
- Administered receptor agonists (alpha-methyl-5-HT, 5-CT) to assess their effects on locomotor patterns.
Main Results:
- Blockade of 5-HT(2) or 5-HT(7) receptors reversibly modulated or blocked locomotion.
- Activation of 5-HT(2) receptors initiated rhythmic activity.
- 5-HT(7) receptor activation led to increased neurogram discharge and rhythmic activity.
- Dopamine D(1) and D(2) receptor blockade disrupted locomotion, especially when combined.
- Co-application of 5-HT(2) and D(1)/D(2) agonists evoked locomotor activity.
Conclusions:
- Serotonin-induced fictive locomotion in neonatal mice is partially mediated by 5-HT(2), 5-HT(7), and dopaminergic receptors.
- These receptor systems interact to regulate the generation and modulation of locomotor patterns.
- The findings highlight the complex interplay of neurotransmitter systems in early motor control development.
