Qualidade de vida, sintomas de depressão e adesão ao tratamento em pacientes com trantorno depressivo maior / Quality of life, depression symptoms and adherence to treatment in patients with major depressive disorder / Calidad de vida, síntomas depresión y adhesión al tratamiento en pacientes con trastorno depresivo mayor

Introdução:Pacientes com depressão maior geralmente respondem ao tratamento com medicamentos antidepressivos, no entanto em 10% a 30% dos casos há apenas uma resposta parcial ou nenhuma resposta, entre os fatores que podem influenciar encontra-se o perfil das enzimas hepáticas metabolizadoras dos antidepressivos, tal como a CYP2C19.Objetivo:Caracterizar os indivíduos quanto ao perfil genético dospolimorfismos CYP2C19*2 ou CYP2C19*17 em pacientes com transtorno depressivo maior (TDM) tratados com citalopram ou escitalopram e compará-los em relação a adesão ao tratamento, sintomas de depressão e qualidade de vida.Metodologia:Trata-se de um estudo transversal realizado com 29 pacientes com TDM. Amostras de sangue foram coletadas para genotipagem de CYP2C19 por discriminação alélica TaqMan®. Após caracterização do perfil genético, os indivíduos foram comparados quanto aos dados demográfico e socioeconômico, adesão ao tratamento (TestedeMorisky-Green),sintomas de depressão (escala de Hamilton) e qualidade de vida (WHOQoL-BREF).Resultados:Quatro pacientes (13.8%) apresentaram polimorfismo para CYP2C19*2 e 10 pacientes (34.4%) para CYP2C19*17, com maior prevalência de CYP2C19*17 (p>0.05). Nenhuma associação significativa de características socioeconômicas, demográficas e clínicas entre os genótipos do CYP2C19.No TestedeMorisky-Green, aadesão moderada ao tratamento foi predominante nos pacientes CYP2C19*2 e CYP2C19*17 (p>0.05). Não foi observada associação entre sintomas de depressão e polimorfismos genéticos (p>0.05). Uma associação significativa entre o genótipo polimórfico CC do CYP2C19*17 com a satisfação com a saúde, enquanto o genótipo CT foi associado ao estado "nem satisfeito/nem insatisfeito" (p<0.05). A maioria dos indivíduos CYP2C19*2 e CYP2C19*17 relatou "necessidade de melhorar" em relação aos domínios de qualidade de vida físico, psicológico, social e ambiental (p>0.05).Conclusões:Os pacientes apresentaram maior prevalência do polimorfismo CYP2C19*17, com moderada adesão ao tratamento. Alguns pacientes, mesmo sob efeito da medicação, apresentaram sintomas de depressão moderado a intenso e relataram uma indefinição na satisfação da sua qualidade de vida (AU).

Introduction:Patients with major depression usually respond to treatment with antidepressant drugs, however in 10% to 30% of cases there is only a partial response or no response, among the factors that can influence is the profile of liver enzymes metabolizing antidepressants, such as CYP2C19.Objective:To characterize the individuals regarding the genetic profile ofCYP2C19*2or CYP2C19*17 polymorphisms in patients with major depressive disorder (MDD) treated with citalopram or escitalopram, and to compare themaccording to treatment adherence, symptoms of depression and quality of life.Methodology:This is cross-sectionalstudy carried out with 29 patients with MDD. Blood samples were collected for CYP2C19 genotyping by TaqMan® allelic discrimination. After characterization of the genetic profile, the individuals were compared regarding the demographic and socioeconomic data, treatment adherence (Morisky-GreenTest), symptoms of depression (Hamilton scale) and quality of life (WHOQoL-BREF).Results:Four patients showed (13.8%) CYP219*2 and 10 patients (34.4%) CYP219*17 polymorphisms.,withhigher prevalence of CYP219*17 (p>0.05). No association between socioeconomic, demographic, and clinical features with CYP2C19 genotypes was observed. In Morisky-GreenTest, moderate adherence to treatment was predominant for CYP2C19*2 and CYP219*17 patients (p>0.05). No statistically significant association was observed between symptoms of depression and genetic polymorphisms (p>0.05). A significant association between polymorphic CC genotype of CYP219*17 with health satisfaction, while the CT genotype was associated with "neither satisfied/nor dissatisfied" status (p<0.05). Most of the CYP2C19*2 and CYP2C19*17 subjects reported "need to improve" or "regular" regarding physical, psychological, social, and environmental domainsof quality of life(p>0.05).Conclusions:The patients showed a higher prevalence of CYP219*17 polymorphism, with moderate treatment adherence. Some subjects, even under the effect of the medication, presented moderate to intense symptoms of depression, and reported a lack of definition in the satisfaction of their quality of life (AU).

Introducción:Los pacientes con depresión mayor responder al tratamiento con antidepresivos, en 10% al 30% de los casos existe una respuesta parcial o nula, entre los factores que pueden influir se encuentra el perfil de enzimas hepáticas metabolizadoras de antidepresivos, como CYP2C19.Objetivo: Caracterizar a los individuos en cuanto al perfil genético depolimorfismos CYP2C19 *2 o CYP2C19 * 17 en pacientes con trastorno depresivo mayor (TDM) tratados con citalopram o escitalopram y compararlos en relaciónpara la adherencia al tratamiento, síntomas de depresión y la calidad de vida.Metodología: Estudio transversalcon 29 pacientes con TDM. Se recogieron muestras de sangre para la determinación del genotipo CYP2C19 mediante discriminación alélica TaqMan®, los individuos fueron comparados en cuanto a los datosdemográficosy socioeconómicos, adherencia (Prueba de Morisky-Green), síntomas de depresión (escala de Hamilton) y calidad de vida (WHOQoL-BREF).Resultados: Cuatro pacientes (13,8%) con polimorfismo CYP2C19*2 y 10 (34,4%) con CYP2C19 * 17,(p> 0,05). No existe una asociación significativa de las características socioeconómicas, demográficas y clínicas con los genotipos CYP2C19. La adherencia moderada al tratamiento fue predominante en los pacientes con CYP2C19*2 y CYP2C19*17 (p> 0,05). No hubo asociación entre síntomas de depresión y polimorfismos genéticos (p> 0.05). Una asociación significativa entre el genotipo polimórfico CYP2C19 * 17 CC con la satisfacción con la salud, mientras que el genotipo CT se asoció con el estado "ni satisfecho / no insatisfecho" (p <0.05). La mayoría de CYP2C19 * 2 y CYP2C19 * 17 individuos informaron "necesidad de mejorar" en relación con los dominios físico, psicológico, social y ambientalde calidad de vida(p> 0,05).Conclusiones: Los pacients mostraron una mayor prevalencia del CYP2C19 * 17, con adherencia moderada al tratamiento, síntomas de depresión moderada a intensay informaron una falta de definición en la satisfacción de su calidad de vida (AU).

Neonatal exposure to citalopram increases pyramidal and granular cell density in dorsal hippocampus of male but not female adult rats: a quantitative Nissl study / La exposición neonatal al citalopram aumenta la densidad de las células piramidales y granulares en el hipocampo dorsal de ratas adultas macho pero no en hembras: un estudio cuantitativo con tinción de Nissl

Antidepressants use during pregnancy was associated with an increased risk of autism spectrum disorders. Animal models based on early life alterations in serotonin availability replicate some of the anatomical and behavioral abnormalities observed in autistic individuals. In recent years there has been a growing interest in the possible role of the hippocampus in autism. The aim of study is to examine the effects of neonatal antidepressant (CTM) exposure during a sensitive period of brain development on pyramidal and granule cells density of hippocampal formation. We examined the pyramidal and granular cells density of dorsal hippocampus using Nissl stained sections obtained from neonatal citalopram (CTM) exposed rats (5 mg/kg, twice daily, s.c.), from postnatal day 8 to 21 (PN8-21), saline and non-exposed rats. The density of pyramidal cells was significantly increased by 10.2 % in CA1, 10.6 % in CA3 and 13.2 % in CA4 in CTM treated compared with non-treated or saline treated animals (p<0.0001). The density of granule cells in the dentate gyrus was significantly increased by 12.0 % in CTM treated compared with non-treated or saline treated animals (p<0.0001). These findings were obtained only from male rats, suggesting a sexual dimorphism in neural development after SSRI exposure. These data suggest that the neonatal exposure to CTM may induce long-lasting changes in the hippcampal formation in adults, and such effects appear to preferentially target males.

El uso de antidepresivos durante el embarazo se asoció con un mayor riesgo de trastornos del espectro autista. Los modelos animales basados en alteraciones tempranas de la vida en la disponibilidad de serotonina replican algunas de las anomalías anatómicas y de comportamiento observadas en individuos autistas. En los últimos años ha habido un interés creciente en el posible papel del hipocampo en el autismo. El objetivo del estudio fue examinar los efectos de la exposición al antidepresivo neonatal (CTM) durante un período sensible del desarrollo cerebral en la densidad de las células piramidales y granulares de la formación del hipocampo. Examinamos la densidad de las células piramidales y granulares del hipocampo dorsal utilizando secciones teñidas con Nissl obtenidas de ratas expuestas al citalopram neonatal (CTM) (5 mg / kg, dos veces al día, sc), desde el día postnatal 8 a 21 (PN8-21), solución salina y ratas no expuestas. La densidad de células piramidales se incrementó significativamente en un 10,2 % en CA1, 10,6 % en CA3 y 13,2 % en CA4 en CTM tratados en comparación con animales no tratados o tratados con solución salina (p <0,0001). La densidad de células granulares en el giro dentado aumentó significativamente en un 12,0 % en los animales tratados con CTM en comparación con los animales no tratados o tratados con solución salina (p <0,0001). Estos hallazgos se obtuvieron solo en ratas macho, lo que sugiere un dimorfismo sexual en el desarrollo neural después de la exposición a ISRS. Estos datos sugieren que la exposición neonatal a la CTM puede inducir cambios de larga duración en la formación del hipocampo en adultos, y estos efectos parecen dirigirse preferentemente a los machos.

The effect of Sertraline, Paroxetine, Fluoxetine and Escitalopram on testicular tissue and oxidative stress parameters in rats

Introduction: The aim of this study was to evaluate the effect of selective serotonin reuptake inhibitors (SSRIs) on testicular tissue and serum malondialdehyde (MDA) levels in rats. Materials and methods: A total of 40 male Wistar albino rats, 5.5-6 months old, were equally divided at random into five groups: group 1 was the control group, group 2 received sertraline 10mg/kg (p.o), group 3 was administered fluoxetine 10mg/kg (p.o), group 4 received escitalopram 10mg/kg (p.o), and group 5 (n = 8) was administered paroxetine 20mg/kg. Each dose was administered orally for two months. Johnsen’s criteria were used to categorize spermatogenesis. Johnsen’s method assigns a score of 1 to 10 to each tubule cross-section examined. In this system, a Johnsen score of 9 and 10 indicates normal histology. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were evaluated. Serum MDA levels were also measured. Results: The mean Johnsen scores were 9.36 ± 0.33, 9.29 ± 0.32, 8.86 ± 0.48, 9.10 ± 0.56, and 8.33 ± 0.90 in control group, sertraline group, fluoxetine group, escitalopram group, and paroxetine group, respectively. The Johnsen score was significantly lower for paroxetine group compared with the control group (p < 0.05). The mean FSH level increased only in the sertraline group. With the exception of the fluoxetine group, the testosterone levels were lower in all groups compared with the control group. The total testosterone level was significantly lower in the sertraline group compared with the control group [40.87 (22.37-46.8) vs. 15.87 (13.53-19.88), p < 0.01]. There were no significant differences between the groups with respect to the MDA and LH levels (p = 0.090 and p = 0.092). Conclusion: These data suggest that SSRIs have a negative effect on testicular tissues. This negative impact is markedly greater in the paroxetine group. To determine the exact ...

Effect of escitalopram on the processing of emotional faces

Serotonin has been implicated in the neurobiology of depressive and anxiety disorders, but little is known about its role in the modulation of basic emotional processing. The aim of this study was to determine the effect of the selective serotonin reuptake inhibitor, escitalopram, on the perception of facial emotional expressions. Twelve healthy male volunteers completed two experimental sessions each, in a randomized, balanced order, double-blind design. A single oral dose of escitalopram (10 mg) or placebo was administered 3 h before the task. Participants were presented to a task composed of six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) that were morphed between neutral and each standard emotion in 10 percent steps. Escitalopram facilitated the recognition of sadness and inhibited the recognition of happiness in male, but not female faces. No drug effect on subjective measures was detected. These results confirm that serotonin modulates the recognition of emotional faces, and suggest that the gender of the face can have a role in this modulation. Further studies including female volunteers are needed.

Possible role of citalopram and desipramine against sleep deprivation-induced anxiety like-behavior alterations and oxidative damage in mice.

Sleep is an essential physiological process for maintaining physical, mental, and emotional health. Sleep deprivation and associated disorders like depression and anxiety are one of the major problems now-days. The present study was designed to explore the neuroprotecitve effect of citalopram and desipramine on 72 hr sleep deprivation-induced behavioral alterations and oxidative damage in mice. Various behavioral tests (plus maze, zero maze, mirror chamber, actophotometer), body weight followed by oxidative parameters (malondialdehyde level, glutathione, catalase, nitrite and protein) were assessed. Treatment with citalopram (5 and 10 mg/kg, ip) and desipramine (10 and 20 mg/kg, ip) for 5 days significantly improved locomotor activity, anti-anxiety like behavior in all paradigms tasks (mirror chamber, plus maze, zero maze) as compared to control (72 hr sleep-deprived). Biochemically, citalopram and desipramine treatment significantly restored depleted reduced glutathione, catalase activity, attenuated raised lipid peroxidation and nitrite level as compared to control (72 hr sleep-deprived) animals. Results of present study suggest that citalopram (5 and 10mg/kg, ip) and desipramine (10 and 20 mg/kg, ip) have neuroprotective effect against sleep deprivation-induced behavior alteration and oxidative damage in mice.

Neonatal exposure to citalopram, a serotonin selective reuptake inhibitor, programs a delay in the reflex ontogeny in rats / Exposição neonatal ao citalopram, um inibidor seletivo da recaptação de serotonina, programa retardo na ontogênese reflexa em ratos

Serotonin influences the growth and development of the nervous system, as well as its behavioral manifestations. The possibility exists that increased brain serotonin availability in young animals modulates their neuro-behavioral responses. This study investigated the body weight gain and reflex ontogeny of neonatal rats treated during the suckling period with two doses of citalopram (5 mg, or 10 mg/kg, sc, daily). The time of the appearance of reflexes (palm grasp righting, free-fall righting, vibrissa placing, auditory startle response, negative geotaxis and cliff avoidance) as well as the body weight evolution were recorded. In general, a delay in the time of reflex development and a reduced weight gain were observed in drug-treated animals. These findings suggest that serotoninergic mechanisms play a role in modulating body weight gain and the maturation of most reflex responses during the perinatal period in rats.

A serotonina influencia o crescimento e o desenvolvimento do sistema nervoso e sua expressão comportamental. O aumento da disponibilidade de serotonina no cérebro de ratos jovens parece modular as respostas neurocomportamentais. Neste estudo, foram investigados o ganho de peso corporal e a ontogênese dos reflexos em ratos neonatos, tratados diariamente, durante o período de aleitamento, com duas doses de citalopram (5 ou 10 mg/Kg de peso corporal, via subcutânea). Foram avaliados, o tempo de aparecimento dos reflexos (preensão palmar, endireitamento, colocação pelas vibrissas, resposta ao susto, geotáxico negativo e aversão ao precipício), e a evolução do peso corporal. Foi observado atraso no tempo de desenvolvimento de alguns reflexos e redução no ganho de peso corporal. Os achados em ratos sugerem que as alterações no ganho de peso corporal e na maturação dos reflexos são programadas, durante o período perinatal, com participação de mecanismos serotoninérgicos de modulação.

Effect of escitalopram and venlafaxine on seizure score and lipid peroxidation in mice receiving carbamazepine antiepileptic therapy

The frequent co-existence of depression in epileptic patients raises the issue of simultaneous use of antidepressants along with anti-epileptic drugs in management of such cases. However, it is necessary to evaluate the safety of these antiepileptic/antidepressant drug combinations. The present study investigates the effect of either antidepressant; escitalopram [selective serotonin reuptake inhibitor, SSRI] or venlafaxine [serotonin/noradrenaline reuptake inhibitor, SNRI], administered alone or in combination, with the conventional antiepileptic drug carbamazepine on chemo-convulsions induced by picrotoxin. In addition, the effect of both antidepressants on lipid peroxidation, as an assumable cause of neuro-degenration in epilepsy, was studied in a model of chronic restraint in mice. The results show enhancement of seizure severity with significant increase in lipid peroxidation upon escitalopram treatment whether alone or in combination with carbamzepine. On the other hand, venlafaxine, administered alone or in combination with carbamazepine, provided significant protection against picrotoxin-induced convulsions as well as lipid peroxidation favoring its application in management of epilepsy-depression co-morbidities

Efeitos do tratamento neonatal com inibidor seletivo de recaptura da 5-HT sobre o desenvolvimento anatômico crânio-encefálico / Neonatal treatment effect with selective inibitor of 5-HT recapture over the cranium-encephalic anatomic development

Pesquisadas repercussões neonatais do tratamento crônico com inibidores seletivos de recaptura da serotonina (ISRS) sobre crescimento somático, do encéfalo e crânio. Ratos machos foram divididos em grupos: controle (NaCl) e Cit (10 æL/Kg citalopram 10 mg). Durante 21 dias pós-natais, foram aferidos peso corporal, eixo látero-lateral, ântero-posterior e circunferência do crânio. Aos 8, 15 e 22 dias pós-natais, os animais foram sacrificados para retirada do encéfalo para avaliar as medidas citadas acima. A utilização de ISRS provocou déficit de crescimento corporal, diminuição das medidas craniais e do encéfalo. O retardo é possivelmente decorrência de alteração na magnitude da ação trófica da serotonina sobre morfogênese crânio-facial, reforçando a participação do sistema serotoninérgico sobre o crescimento somático e ontogenético. O possível efeito hipofágico dos ISRS não é descartado.

Neonatal repercussion researched of the serotonin selective recapture inibitor (SSRI) chronic treatment about the somatic growth, of the encephalon and skull. Male rats were divided into groups: control (NaCl) and Cit (10 æL/Kg citalopram 10 mg). In 21 post birth days were measured body weight, side axle , front and rear and skull circle. At 8, 15, 22 days after birth, animals were sacrified for the encephalon withdrawal to evaluate the measurements mentioned above. SSRI use caused body growth deficit, skull and encephalon reduction. The retard is possibly caused by the magnitude change of the trophic serotonin action over the skull-facial morphogenesis, reinforcing the serotoninergic system participation over the somatic and ontogenic growth. The SSRI possible hypophagic effects are not discarded.

Usefulness of serotoninergic challenge with oral citalopram / Utilidade do desafio serotoninérgico com citalopram oral

OBJECTIVE: Challenge tests designed to evaluate serotoninergic pathways have widely used intravenous citalopram. Oral citalopram has also been used, but unsatisfactory results were obtained with a dose of 20 mg. The objective of this study was to determine whether a higher oral dose would reproduce similar to those described for intravenous administration. To that end, we evaluated cortisol, growth hormone and prolactin levels. METHOD: Eight healthy male volunteers were evaluated in a randomized crossover challenge test with 40 mg of oral citalopram or placebo. RESULTS: Cortisol levels increased at 2-4h after the oral citalopram intake, with a small amplitude peak occurring in two-thirds of the subjects. Levels of prolactin and growth hormone remained unchanged throughout the study. CONCLUSION: The use of oral citalopram might present an alternative in serotoninergic challenge tests, but higher doses are required.

OBJETIVO: Testes-desafio desenvolvidos para avaliar as vias serotoninérgicas utilizaram amplamente citalopram intravenoso. Citalopram oral também foi utilizado, mas obtiveram-se resultados insatisfatórios com uma dose de 20 mg. O objetivo deste estudo foi o de determinar se uma dose oral mais elevada poderia reproduzir resultados similares aos descritos para administração intravenosa. Com esta finalidade, avaliamos os níveis de cortisol, de hormônio do crescimento e de prolactina. MÉTODO: Oito voluntários do sexo masculino saudáveis foram avaliados em um teste-desafio cruzado, aleatorizado, com 40 mg de citalopram oral ou placebo. RESULTADOS: Os níveis de cortisol aumentaram após 2-4 horas da ingestão de citalopram oral, com um pequeno pico de amplitude ocorrendo em dois terços dos indivíduos. Os níveis de prolactina e de hormônio de crescimento permaneceram inalterados ao longo do estudo. CONCLUSÃO: O uso de citalopram oral poderia apresentar uma alternativa em testes-desafio serotoninérgicos, mas doses maiores são necessárias.

Action of selective serotonin reuptake inhibitor on aggressive behavior in adult rat submitted to the neonatal malnutrition

The effect of the malnutrition during suckling on the aggressiveness was investigated in adult rats treated or not with citalopram, a selective serotonin reuptake inhibitor (SSRI). The animals were divided into two groups according to the diet used: nourished groupó the rats received the control diet with 23 per cent protein during the life; and malnourished groupó the rats had its mothers submitted to diet with 7.8 per cent protein during suckling. At 120 days of age, each group was sub-divided according to the treatment: acute ó consisting a single i.p. injection of saline solution or 20-mg/Kg citalopram; chronic ó consisting the single injections (1 per day during 14 days) of saline or 20 mg/Kg citalopram. The acute or chronic treatment with SSRI reduces aggressive response in nourished rats, but not in malnourished ones. Thus, the malnutrition during the critical period of brain development seems to induce durable alterations in the function of the serotoninergic neurotransmission

Reduction of intraspecific aggression in adult rats by neonatal treatment with a selective serotonin reuptake inhibitor

Most studies suggest that serotonin exerts an inhibitory control on the aggression process. According to experimental evidence, this amine also influences growth and development of the nervous tissue including serotoninergic neurons. Thus, the possibility exists that increased serotonin availability in young animals facilitates a long-lasting effect on aggressive responses. The present study aimed to investigate the aggressive behavior of adult rats (90-120 days) treated from the 1st to the 19th postnatal day with citalopram (CIT), a selective serotonin reuptake inhibitor (20 mg/kg, sc, every 3 days). Aggressive behavior was induced by placing a pair of rats (matched by weight) in a box (20 x 20 x 20 cm), and submitting them to a 20-min session of electric footshocks (five 1.6-mA - 2-s current pulses, separated by a 4-min intershock interval). When compared to the control group (rats treated for the same period with equivalent volumes of saline solution), the CIT group presented a 41.4 percent reduction in the duration of aggressive response. The results indicate that the repeated administration of CIT early in life reduces the aggressive behavior in adulthood and suggest that the increased brain serotoninergic activity could play a role in this effect

Hiponatremia e hipokalemia graves, recientes, asociadas a hidroclorotiazida, enalaprila y citalopram: caso clínico / Severe and recent hyponatremia and hypokalemia associated to the use of hydrochlorothiazide, enalapril and cytalopram: clinical case

We report a 72 years old hypertensive female, treated with enalapril 10 mg/day and hydrochlorothiazide 25 mg/day during three years. She presented a depressive disorder and cytalopram was prescribed in a dose of 10 mg/day. Two weeks before admission, a serum electrolyte analysis disclosed normal results and the cytalopram dose was increased to 20 mg/day. The patient was admitted with a hyponatremic encephalopathy with a plasma sodium of 100 mEq/L and a plasma potassium of 2.0 mEq/L. cytalopram, enalapril and hydrochlorothiazide were discontinued, hypertonic NaCl and KCl were administered. The patient had a favorable evolution with a remarkable improvement of her symptoms

Serotonergic modulation of footshock induced aggression in paired rats.

Footshock induced aggression (FIA) was induced in paired rats and three paradigms of aggressive behaviour were recorded, namely, latency to fight (LF), total period of physical contact (TPP) and cumulative aggression scores (CAS). The effects of increasing or decreasing central serotonergic activity, by using a number of pharmacological agents with well defined effects on rat brain serotonin, were investigated on FIA and on FIA augmented by apomorphine, a dopamine receptor agonist. The results show that centrally administered serotonin, the serotonin precursor, 5-hydroxytryptophan administered with clorgyline, a selective MAO A inhibitor, quipazine, a serotonin receptor agonist, and fluoxetine, a selective inhibitor of neuronal re-uptake of serotonin, attenuated all paradigms of FIA and apomorphine induced potentiation of FIA. On the contrary, the other re-uptake inhibitor used, citalopram, appeared to have a dual effect and decreased LF and CAS, while increasing TPP. The serotonin synthesis inhibitor, p-chlorophenylalanine and the selective serotonin receptor (5-HT2) antagonist, ketanserin, augmented all paradigms of FIA per se and apomorphine induced augmentation of FIA. However, the other serotonin receptor antagonist used, metergoline, which blocks both 5-HT1 and 5-HT2 receptor subtypes, attenuated FIA per se but decreased only CAS in apomorphine induced increase in FIA. The data confirm the inhibitory effect of the central serotonergic system on aggressive behaviour and the inverse relationship existing between it and the central dopaminergic system in the modulation of FIA, as has also been confirmed in earlier biochemical investigations from this laboratory. The data has been discussed in the light of existing knowledge on serotonin receptor subtypes and the presence of modulatory serotonergic heteroreceptors on central dopaminergic neurones.