;; Reference: Theta-Frequency Bursting and Resonance in Cerebellar Granule Cells:Experimental
;; Evidence and Modeling of a Slow K+-Dependent Mechanism
;; Egidio D'Angelo,Thierry Nieus,Arianna Maffei,Simona Armano,Paola Rossi,Vanni Taglietti,
;; Andrea Fontana and Giovanni Naldi

(nemo-model Golgi_Na

  (
   (input v celsius)

   (defun linoid (x y) 
    	 (if ((abs (x / y)) < 1e-6) 
             then (y * (1 - ((x / y) / 2)))
	     else (x / (1 - exp (x / y) ))
	      ))


   (component (type ionic-current) (name Na )
	      
	      (component (type gate)

			 ;; rate constants
			 (Q10 = (pow (3 ((celsius - 20) / 10))))

			 (const Aalpha_m  = 0.3)
			 (const Kalpha_m  = -10)
			 (const V0alpha_m = -25)
	
			 (const Abeta_m  = 12)
			 (const Kbeta_m  = -18.182)
			 (const V0beta_m = -50)

			 (const Aalpha_h  = 0.21)
			 (const Kalpha_h  = -3.333)
			 (const V0alpha_h = -50)
 
			 (const Abeta_h  = 3)
			 (const Kbeta_h  = -5)
			 (const V0beta_h = -17)

			 ;; rate functions
			 (defun alpha_m (v Q10)	
			   (Q10 * Aalpha_m * linoid((v - V0alpha_m) Kalpha_m) ))

			 (defun beta_m (v Q10)
			   (Q10 * Abeta_m * exp((v - V0beta_m) / Kbeta_m) ))

			 (defun alpha_h (v Q10)
			   (Q10 * Aalpha_h * exp((v - V0alpha_h) / Kalpha_h) ))	
				
			 (defun beta_h (v Q10)
			   (Q10 * Abeta_h / (1 + exp((v - V0beta_h) / Kbeta_h) )))

			 
			 (hh-ionic-gate 
			  (Na  ;; ion name: exported variables will be of the form {ion}_{id}
			   (initial-m  ((alpha_m (v Q10)) / (alpha_m (v Q10) + beta_m (v Q10)) ))
			   (initial-h  ((alpha_h (v Q10)) / (alpha_h (v Q10) + beta_h (v Q10)) ))
			   (m-power    3)
			   (h-power    1)
			   (m-alpha    (alpha_m (v Q10)))
			   (m-beta     (beta_m (v Q10)))
			   (h-alpha    (alpha_h (v Q10)))
			   (h-beta     (beta_h (v Q10)))
			   ))
			 
			 )
	      
	      (component (type pore)
			 (const  gbar  = 0.048)
			 (output gbar ))

	      
	      (component (type permeating-ion) (name na)
			 (const e = 87.39)
			 (output e ))
	      
	      ) ;; end Na current


   (component (type voltage-clamp) (name Na)

	      (const vchold   = -71)
	      (const vcbase   = -60)
	      (const vcinc    = 10)
	      (const vcsteps  = 9)
	      (const vchdur   = 30)
	      (const vcbdur   = 100)
           
	      (output vchold vcbase vcinc vcsteps vchdur vcbdur))

))