Perioral Movements Research Articles

Facial Expressions of Emotion in Children with Cleft Lip and Palate.

To examine the facial movements children with cleft lip and palate (CLP) employ to express basic emotions. Ability of observers to interpret facial expressions of children with CLP was also considered. Prospective case-control design. Outpatient craniofacial anomalies clinic. Twenty-five children with CLP (age 8 to 12) and 25 age/sex-matched controls. Children were video recorded making facial expressions representing anger, disgust, fear, happiness, sadness, and surprise. Magnitude of children's facial movements was quantified and compared using OpenFace. Subsequently, emotion videos were presented to 19 adults who were asked to identify the emotion conveyed in each facial expression. Accuracy of emotion recognition was compared across groups. Compared with controls, children with CLP employed significantly (P < .05) smaller magnitude superior and lateral perioral movements to express disgust (Cohen's d = .50), happiness (Cohen's d = 1.1), and fear (Cohen's d = .93). For disgust and sadness, children with CLP employed significantly greater magnitude movements of the nose and chin, presumably to compensate for reduced perioral range of motion. For anger, happiness, and sadness, children with CLP employed smaller magnitude movements of the upper face when compared with controls. Observers identified disgust (OR = 1.26), and fear (OR = 2.44) significantly less accurately in children with CLP when compared with controls. Children with CLP employed different facial movements to express certain emotions. Observers less accurately identified some emotions conveyed by facial expressions in children with CLP when compared with controls, likely due in part to differences in facial movements. Future research should explore the implications of these differences for social communication.

Emotional facial expression and perioral motor functions of the human auditory cortex

ObjectiveWe investigated the role of transverse temporal gyrus and adjacent cortex (TTG+) in facial expressions and perioral movements. MethodsIn 31 patients undergoing stereo-electroencephalography monitoring, we describe behavioral responses elicited by electrical stimulation within the TTG+. Task-induced high-gamma modulation (HGM), auditory evoked responses, and resting-state connectivity were used to investigate the cortical sites having different types of responses on electrical stimulation. ResultsChanges in facial expressions and perioral movements were elicited on electrical stimulation within TTG+ in 9 (29%) and 10 (32%) patients, respectively, in addition to the more common language responses (naming interruptions, auditory hallucinations, paraphasic errors). All functional sites showed auditory task induced HGM and evoked responses validating their location within the auditory cortex, however, motor sites showed lower peak amplitudes and longer peak latencies compared to language sites. Significant first-degree connections for motor sites included precentral, anterior cingulate, parahippocampal, and anterior insular gyri, whereas those for language sites included posterior superior temporal, posterior middle temporal, inferior frontal, supramarginal, and angular gyri. ConclusionsMultimodal data suggests that TTG+ may participate in auditory-motor integration. SignificanceTTG+ likely participates in facial expressions in response to emotional cues during an auditory discourse.

Functional and structural correlates of abnormal involuntary movements in psychosis risk and first episode psychosis

BackgroundAbnormal involuntary movements (AIM) may occur throughout the course of psychosis. While AIM are thought to indicate striatal abnormalities, the functional and structural correlates of increased AIM remain elusive. Here, we examined the prevalence of AIM in patients with clinical high risk for psychosis (CHR), first episode psychosis (FEP) and clinical controls (CC). Furthermore, we tested the association of AIM with regional cerebral blood flow (rCBF), grey matter volume (GMV), and premorbid IQ. MethodsWe conducted a video-based analysis of AIM in patients with CHR (n = 45), FEP (n = 10) and CC (n = 39), recruited in the Early Detection and Intervention Center, Bern. Premorbid intelligence was evaluated using the Peabody Picture Vocabulary test. Additionally, arterial spin labeling MRIs and structural MRIs were acquired in a subgroup of the sample to investigate the association of AIM with rCBF and GMV. ResultsHigher total AIM scores were detected in CHR (p = 0.02) and FEP (p = 0.04) as compared to CC. When separated for different muscle groups, lips and perioral movements were significantly increased in CHR patients as compared to CC (p = 0.009). AIM scores correlated positively with rCBF in the premotor cortex, Brodmann area 6 (p < 0.05, FWE corrected). Negative correlations were found between AIM and GMV of the corresponding caudal middle frontal gyrus (p = 0.04, FWE corrected) and premorbid intelligence (p = 0.02). ConclusionsAIM were more frequent in the psychosis spectrum than in clinical controls. Neuroimaging findings indicate an involvement of cortical motor areas in abnormal motor behavior, instead of pure basal ganglia pathology.

Leveraging audiovisual speech perception to measure anticipatory coarticulation.

A noninvasive method for accurately measuring anticipatory coarticulation at experimentally defined temporal locations is introduced. The method leverages work in audiovisual (AV) speech perception to provide a synthetic and robust measure that can be used to inform psycholinguistic theory. In this validation study, speakers were audio-video recorded while producing simple subject-verb-object sentences with contrasting object noun rhymes. Coarticulatory resistance of target noun onsets was manipulated as was metrical context for the determiner that modified the noun. Individual sentences were then gated from the verb to sentence end at segmental landmarks. These stimuli were presented to perceivers who were tasked with guessing the sentence-final rhyme. An audio-only condition was included to estimate the contribution of visual information to perceivers' performance. Findings were that perceivers accurately identified rhymes earlier in the AV condition than in the audio-only condition (i.e., at determiner onset vs determiner vowel). Effects of coarticulatory resistance and metrical context were similar across conditions and consistent with previous work on coarticulation. These findings were further validated with acoustic measurement of the determiner vowel and a cumulative video-based measure of perioral movement. Overall, gated AV speech perception can be used to test specific hypotheses regarding coarticulatory scope and strength in running speech.

Perioral movements and sucking pattern during bottle feeding with a novel, experimental teat are similar to breastfeeding

To measure intraoral pressure and perioral movement in infants during breastfeeding (BF) and feeding with experimental teat (ET). The teat has a wide base, firm shaft and a valve at the base, such that milk flows only when the baby provides a hold pressure. Twenty healthy term infants, between 1 and 8 months old, were enrolled in the study. Feeding sessions (BF and ET) were recorded using a digital video camera. During both BF and ET feeding sessions, recordings during feeding were taken of jaw and throat movements (n=20) as well as intraoral pressure (n=18). The efficiency of milk transfer and the angle of the mouth were also measured. There was no significant difference in either the jaw or throat movements between BF and ET. The sucking burst pattern, the efficiency (ml min(-1)), and the angle of the mouth did not differ between both feeding methods. The intraoral negative pressure observed during ET was significantly smaller than that observed during BF. There were no significant differences in perioral movements. Although the value was smaller, a hold pressure was observed during ET. From these results, the novel, ET may decrease BF problems related to bottle use.

Complex movement disorders at disease onset in childhood narcolepsy with cataplexy

Narcolepsy with cataplexy is characterized by daytime sleepiness, cataplexy (sudden loss of bilateral muscle tone triggered by emotions), sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep. Narcolepsy with cataplexy is most often associated with human leucocyte antigen-DQB1*0602 and is caused by the loss of hypocretin-producing neurons in the hypothalamus of likely autoimmune aetiology. Noting that children with narcolepsy often display complex abnormal motor behaviours close to disease onset that do not meet the classical definition of cataplexy, we systematically analysed motor features in 39 children with narcolepsy with cataplexy in comparison with 25 age- and sex-matched healthy controls. We found that patients with narcolepsy with cataplexy displayed a complex array of ‘negative’ (hypotonia) and ‘active’ (ranging from perioral movements to dyskinetic–dystonic movements or stereotypies) motor disturbances. ‘Active’ and ‘negative’ motor scores correlated positively with the presence of hypotonic features at neurological examination and negatively with disease duration, whereas ‘negative’ motor scores also correlated negatively with age at disease onset. These observations suggest that paediatric narcolepsy with cataplexy often co-occurs with a complex movement disorder at disease onset, a phenomenon that may vanish later in the course of the disease. Further studies are warranted to assess clinical course and whether the associated movement disorder is also caused by hypocretin deficiency or by additional neurochemical abnormalities.

Ictal video-polygraphic features of perioral myoclonia with absences

There have been few case reports of perioral myoclonia with absences (POMA) because of the lack of video-polygraphic recordings clarifying the electroencephalogram (EEG)–electromyogram (EMG) correlations. We describe one of the first video-polygraphic studies of POMA in a patient who underwent repeated and prolonged split-screen video-polygraphic recordings. The ictal EEG showed generalized and irregular discharges of spikes or multiple spikes and slow waves, while two concomitant EMG patterns appeared: (1) a rhythmic enhancement of the orbicularis oris and masseter muscles on both sides with minimal asymmetry corresponding to perioral movements, and (2) a progressive increment in muscular tone in the mylohyoideus muscle corresponding to oroalimentary automatisms. Myoclonic jerks were inconstantly time-locked to the spike component of the spike–wave complex. The evidence of a complex pattern of activation of the facial muscles suggests that the involvement of subcortical central pattern generators, related to masticatory activity, through the disinhibitory effect of the spike–wave discharge is a possible pathophysiological mechanism underlying POMA.

Dopamine antagonistic effects of a series of analogues of oxiperomide and spiroxatrine measured behaviourally in the rodent.

The activity spectra of oxiperomide, spiroxatrine and analogues were determined in two experimental models of abnormal peri-oral movements (induced by intrastriatal dopamine and subcutaneously administered 2-(NN-dipropyl)amino-5,6-dihydroxy-1,2,3,4-tetrahydronaphthalene (NN-diPr-5,6-diOHATN) in the guinea-pig), and in a stereotypy test (induced by subcutaneous apomorphine in the guinea-pig); the ability of the test compounds to induce catalepsy or catatonia in the rat was also determined. The parent compounds oxiperomide and spiroxatrine possessed optimal activity in all tests, although responses to the series of compounds allowed clear differentiation between an ability to antagonize the peri-oral movements (dopamine- or NN-di Pr-5,6-diOHATN induced) and an ability to antagonize apomorphine stereotypy. However, all compounds that antagonized the abnormal peri-oral movements also caused catalepsy/catatonia. The results are considered in terms of the selection of suitable agent(s) for the treatment of peri-oral dyskinesias.

Possible Rabbit Syndrome With Amisulpride

Back to table of contents Previous article Next article LETTERFull AccessPossible Rabbit Syndrome With AmisulprideDattatreya Namdeorao Mendhekar D.P.M., M.D.,Dattatreya Namdeorao Mendhekar D.P.M., M.D.Search for more papers by this author,Published Online:1 Jul 2010https://doi.org/10.1176/jnp.2010.22.3.352.e23AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: Recently, rabbit syndrome has been reported with newer antipsychotic drugs such as clozapine, risperidone, olanzapine, and aripiprazole. 1 We report the case of an elderly man with depressive disorder who developed rabbit syndrome as an acute extrapyramidal side effect after addition of amisulpride to ongoing mianserin therapy. To our knowledge, this is the first case report in the existing literature of rabbit syndrome associated with amisulpride. Case ReportMr. A, a 78-year-old man, presented with a history of depression, diurnal variation of mood, nihilistic delusion, and disturbed biological functions of 4 months’ duration. His brother had bipolar disorder; however, there was no family history of movement disorder. Mr. A’s hypertension was well stabilized with amlodipine, 5 mg/day, for the last 5 years. The diagnosis of major depression with psychotic features was established according to DSM-IV criteria. All his routine investigations were within normal limits except lipid profile. Initially, he was treated with mianserin, 15 mg/day, and olanzapine, 2.5 mg/day, but olanzapine was stopped due to drowsiness and the dose of mianserin was gradually increased to 30 mg per day. Since there was no improvement in his depressive and psychotic symptoms even after taking this medicine for 4 weeks, 50 mg of amisulpride was added and subsequently increased to 150 mg/day over a period of 10 days. In addition, he was also taking alprazolam, 0.5 mg/day, and lorazepam, 1 mg/day. On the fifth day of amisulpride therapy, an abrupt onset of abnormal perioral movements was noticed. These were rapid, fine, and rhythmic involuntary movements of lip and jaw on a vertical axis. Detailed examination also revealed mild parkinsonian symptoms in the form of rigidity, bradykinesia, tremor, and salivation but no dystonic reaction. Estimation of abnormal movements by abnormal involuntary movement scale provided a score of 9. An MRI scan of his head and an EEG were within normal limits. A diagnosis of rabbit syndrome was made, and amisulpride was replaced by trihexyphenidyl, 4 mg/day. On the sixth day of trihexyphenidyl therapy, all perioral movements as well as parkinsonian symptoms subsided. Trihexyphenidyl was gradually withdrawn over the next 2 weeks. A further 2 weeks later, the patient did not report for his scheduled appointment and was subsequently lost to follow-up.Discussion As noticed in our case, a large majority of cases with rabbit syndrome also have other signs of drug-induced parkinsonism. 2 One can argue that mianserin might have been a contributory factor in the emergence of rabbit syndrome as there was a single report of oral dyskinesia and torticollis associated with mianserin. 3 It is also possible that mianserin might have potentiated the motor side effects of amisulpride by increasing the amisulpride level. However, our case did not developed rabbit syndrome while he was on mianserin as a monotherapy. Further, amisulpride is substituted benzamides with high affinity and selectivity for the dopamine D2 and D3 receptors mainly responsible for dyskinesia, 4 whereas mianserin has no or little effect on the dopaminergic system. 3 Clinicians who prescribe amisulpride ought to be aware of this adverse effect. Department of Psychiatry, Neuropsychiatry and Headache Clinic, Delhi, India

Neonatal sucking behavior: Comparison of perioral movement during breast‐feeding and bottle feeding

The aim of the present study was to compare orofacial motion and mouth angle during breast-feeding and bottle feeding in normal infants. Thirteen normal infants were enrolled in the study, and feeding sessions were recorded using a digital video camera at 4 or 5 days following birth. The analysis was successfully performed for 12 infants during both breast-feeding and bottle feeding. Markers were placed at the lateral angle of the eye, the tip of the jaw, and the throat region. Jaw and throat region movements were calculated using the direct linear transformation method. The angle of the mouth was also measured. Throat region movement was significantly larger than jaw movement in both breast-feeding (eye-throat region changes: 1.51 +/- 0.37 mm, eye-jaw changes: 0.91 +/- 0.31 mm, P < 0.001) and bottle feeding (eye-throat region changes: 2.91 +/- 0.46 mm, eye-jaw changes: 1.77 +/- 0.33 mm, P < 0.001). Jaw and throat region movements were significantly smaller during breast-feeding than those during bottle feeding (P < 0.001). The angle of the mouth during breast-feeding is larger than that during bottle feeding (P < 0.001). There was a negative correlation between the angle of the mouth and jaw movement. Jaw and throat region movements during bottle feeding differ from those during breast-feeding. This partly results from the difference in the angle of the mouth during feeding.

Does the degree of smoking effect the severity of tardive dyskinesia? A longitudinal clinical trial

Background Tardive dyskinesia (TD) is a movement disorder observed after chronic neuroleptic treatment. Smoking is presumed to increase the prevalence of TD. The question of a cause-effect-relationship between smoking and TD, however, remains to be answered. Purpose of this study was to examine the correlation between the degree of smoking and the severity of TD with respect to differences caused by medication. Method We examined 60 patients suffering from schizophrenia and TD. We compared a clozapine-treated group with a group treated with typical neuroleptics. Movement disorders were assessed using the Abnormal-Involuntary-Movement-Scale and the technical device digital image processing, providing rater independent information on perioral movements. Results We found a strong correlation (.80 < r < .90, always p < .0001) between the degree of smoking and severity of TD. Repeated measurements revealed a positive correlation between changes in cigarette consumption and changes of the severity of TD ( p < .0001). Analyses of covariance indicated a significant group-effect with a lower severity of TD in the clozapine-group compared to the typical-neuroleptics-group ( p = .010). Interaction-analyses indicated a higher impact of smoking on the severity of TD in the typical-neuroleptics-group compared to the clozapine-group ( p = .033). Conclusion Concerning a possible cause-effect-relationship between smoking and TD, smoking is more of a general health hazard than neuroleptic exposure in terms of TD.

Perioral myoclonia with absences: An overlooked and misdiagnosed generalized seizure type

Objective The goal of this report is to draw attention to perioral myoclonia with absences, a rare and underrecognized generalized seizure type. Methods We describe a 31-year-old, mildly retarded patient who had absence seizures with prominent perioral movements and rare generalized tonic–clonic convulsions. He had an attack of status epilepticus consisting of asymmetrical perioral myoclonic jerks and was misdiagnosed with epilepsia partialis continua. Results The perioral myoclonia were associated with brief lapses of consciousness and with a generalized EEG pattern as shown by the synchronous video/EEG investigation with polygraphic recordings. The patient was diagnosed as having the syndrome of perioral myoclonia with absences described by C.P. Panayiotopoulos, C.D. Ferrie, S.E. Giannakodimos, and R.O. Robinson (in: Wolf P, editor. Epileptic seizures and syndromes. London: John Libbey; 1994, p. 143–53). Conclusion We emphasize that this rare and peculiar seizure type associated with generalized epilepsy can be misdiagnosed as focal epilepsy.

A Korean kindred with autosomal dominant nocturnal frontal lobe epilepsy and mental retardation.

A Korean family had distinctive clinical and neuroimaging features and carried the same genetic mutation that was found in a previously described Japanese kindred with autosomal dominant nocturnal frontal lobe epilepsy. To describe the first Korean family with autosomal dominant nocturnal frontal lobe epilepsy. Members of a large family, including 9 affected individuals from 3 generations, underwent a comprehensive genetic, clinical, electroencephalographic, neuropsychological, and neuroimaging evaluation. Affected members were tested for possible mutations in transmembrane regions 1 through 3 of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4) by direct sequencing and subsequent restriction analysis. Seizures began in childhood, presenting as nocturnal episodes of staring, confusion, shouting, perioral movements, unintelligible speech, and hand waving. Some patients had ictal or interictal epileptiform activity in the temporal and/or frontocentral areas. Neurological examination and brain magnetic resonance imaging results showed no abnormalities, except that all patients available for testing had mild to moderate mental retardation. Fluorodeoxyglucose F 18 with positron emission tomography showed mild decreased glucose uptake in the superior and middle frontal regions, more so on the left than on the right. Patient response to carbamazepine was poor. All affected members were heterozygous for the CHRNA4 Ser252Leu mutation. Disorders associated with mutations in the transmembrane region 2 of CHRNA4 are genetically and phenotypically heterogeneous. Distinctive features of this kindred include (1) mental retardation in all affected members available for testing, (2) abnormal brain findings on fluorodeoxyglucose F 18 with positron emission tomography, (3) poor response to carbamazepine, and (4) full penetrance.

Spaciostructural analyses of mandibular and perioral soft tissue movements during mastication.

We considered that elucidation of the movements of perioral soft tissues during mastication would be useful in evaluating masticatory movements. However, evaluation of movements specific to soft tissues is difficult because movements of the surface of the lower face during mastication include movements of the muscles of facial expression and mandibular movements. The aims of this study were to elucidate the influence of mandibular movements on perioral soft tissue movements during mastication using principal component analysis (PCA) and to abstract the component of movement specific to soft tissues in order to evaluate masticatory movements from the movements of perioral soft tissues. The subjects were 10 healthy persons with complete natural dentition. The experimental food used in this study was sufficiently softened chewing gum. The results of this study showed that the movements of mandibular and perioral soft tissue were closely related in the first and third PCs; in other words, the second PC was the component of movement specific to soft tissues. Thus, elucidation of the second PC is useful for evaluation of masticatory movements from movements of perioral soft tissues.

Tactile Responses in the Granule Cell Layer of Cerebellar Folium Crus IIa of Freely Behaving Rats

We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

Application of principal component analysis to the elucidation of perioral soft tissue movements during mastication

We considered that elucidation of the movements of perioral soft tissue during mastication would be useful in evaluating masticatory movements. However, the evaluation of these movements is difficult because multivariable analysis is needed. In this study, we considered whether principal component analysis (PCA), a form of the multivariate analysis, can reduce the number of degrees of freedom (d.f.) of perioral skin movements (i.e. the time-series data with 45 d.f.). The subjects were 15 healthy persons with complete natural dentition. The chosen experimental food for this study was sufficiently softened chewing gum. Over 95% of the perioral soft tissue movements of healthy subjects with complete natural dentition during mastication could be expressed by PCA using the first three principal components (PCs). Therefore, perioral soft tissue movements in these subjects during mastication were considered to be spatially smooth. Moreover, time analysis of these movements was made possible by the application of proportion diagrams. The results of this study showed that the spatiostructural and temporal analyses of the movements of perioral soft tissue during mastication made possible by the application of PCA.

Application of principal component analysis to the elucidation of perioral soft tissue movements during mastication

Application of principal component analysis to the elucidation of perioral soft tissue movements during mastication

Perioral myoclonia with absence seizures: a rare epileptic syndrome

ABSTRACT We present the clinical and video‐EEG data on an epileptic boy whose absence seizures with marked perioral movements had started at the age of 1.5 years. From age 12 years, he experienced frequent episodes of typical absence status epilepticus (ASE) lasting 1‐2 hours with marked perioral myoclonia and moderate confusion. Initial therapy with carbamazepine was substituted by valproate because of worsening of the absence seizures. At the age of 17, the patient was admitted to our clinic with his usual, but long lasting ASE attack, accompanied by 2 generalized tonic‐clonic convulsions. ASE was confirmed with the EEG which showed continuous 3 Hz spike and wave paroxysms with occasional normal intervals of 1‐5 seconds. IV injection of clonazepam improved the clinical and EEG findings immediately. Video‐ EEG examination performed after a few weeks demonstrated typical absence seizures with perioral myoclonia. Based on the characteristics of seizure semiology, other clinical data and EEG findings, the patient was diagnosed as having the syndrome of “perioral myoclonia with absence seizures” described by Panayiotopoulos.

Behavioral responsitivity to dopamine receptor agonists after extensive striatal dopamine lesions during development

Dopamine (DA) receptor responsitivity was investigated in adult rats that received intrastriatal (i.s.) injections of 6-OHDA (20 micrograms per striatum) on day of birth or postnatal Day 1 (Day 0/Day 1). Neonatally lesioned rats exhibited self-biting behavior and increases in stereotypic gnawing following treatment with the mixed D1/D2 receptor agonist apomorphine (0.32-3.2 mg/kg) or the D1-like receptor agonist SKF38393 (10 mg/kg). Increases in locomotor activity, rearing, and paw treading were also observed in the lesioned rats after SKF38393 (1-10 mg/kg) treatment. The incidences of the prototypical D1 receptor-mediated behaviors, grooming and abnormal perioral movements (i.e., oral dyskinesias) were not increased in the lesioned rats. However, the low dose (0.32 mg/kg) of apomorphien as well as all doses of the D2-like receptor agonist quinpirole (0.32-3.2 mg/kg) induced grooming in the lesioned rats, which was not observed in nonlesioned control rats. Autoradiographs of [3H]mazindol binding to high affinity DA uptake sites revealed an extensive loss of DA terminals in the striata of the neonatally lesioned rats. These data suggest that near-total (> or = 95%) DA depletions on Day 0/Day 1 result in long-term alterations in the functional sensitivity of DA receptors, as well as possible changes in the interactions between D1 and D2 receptors. Comparisons of these results with those seen following lesions of the early-developing DA system ("patch-selective" lesions) and lesions made at other time points will be discussed.

Behavioral responsitivity to dopamine receptor agonists after extensive striatal dopamine lesions during development

Dopamine (DA) receptor responsitivity was investigated in adult rats that received intrastriatal (i.s.) injections of 6-OHDA (20 μg per striatum) on day of birth or postnatal Day 1 (Day 0/Day 1). Neonatally lesioned rats exhibited self-biting behavior and increases in stereotypic gnawing following treatment with the mixed D1/D2 receptor agonist apomorphine (0.32–3.2 mg/kg) or the D1-like receptor agonist SKF38393 (10 mg/kg). Increases in locomotor activity, rearing, and paw treading were also observed in the lesioned rats after SKF38393 (1–10 mg/kg) treatment. The incidences of the prototypical D1 receptor-mediated behaviors, grooming and abnormal perioral movements (i.e., oral dyskinesias) were not increased in the lesioned rats. However, the low dose (0.32 mg/kg) of apomorphine as well as all doses of the D2-like receptor agonist quinpirole (0.32–3.2 mg/kg) induced grooming in the lesioned rats, which was not observed in nonlesioned control rats. Autoradiographs of [3H]mazindol binding to high affinity DA uptake sites revealed an extensive loss of DA terminals in the striata of the neonatally lesioned rats. These data suggest that near-total (≥95%) DA depletions on Day 0/Day 1 result in long-term alterations in the functional sensitivity of DA receptors, as well as possible changes in the interactions between D1 and D2 receptors. Comparisons of these results with those seen following lesions of the early-developing DA system (“patch-selective” lesions) and lesions made at other time points will be discussed. © 1998 John Wiley & Sons, Inc. Dev Psychobiol 32: 313–326, 1998