;; 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 CGC_KV

  (
   (input v
    (cai from ion-pools)
    (ica from ion-currents))

   (const Vrest = -68)
	     
   (const fix_celsius = 30)

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

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

			 ;; rate constants
			 (const Q10 = (pow (3 ((fix_celsius - 6.3) / 10))))

			 (const Aalpha_n = -0.01)
			 (const Kalpha_n = -10)
			 (const V0alpha_n = -25)
			 (const Abeta_n = 0.125)
	
			 (const Kbeta_n = -80)
			 (const V0beta_n = -35)

			 ;; rate functions
			 (defun alpha_n (v) 
			   (Q10 * Aalpha_n * linoid ((v - V0alpha_n) Kalpha_n)))

			 (defun beta_n (v) 
			   (Q10 * Abeta_n * exp((v - V0beta_n) / Kbeta_n) ))

			 (hh-ionic-gate 
			  (KV  ;; ion name: exported variables will be of the form {ion}_{id}
			   (initial-m  ((alpha_n (v)) / (alpha_n (v) + beta_n (v)) ))
			   (m-power    4)
			   (h-power    0)
			   (m-alpha    (alpha_n(v)))
			   (m-beta     (beta_n(v)))
			   ))
			 )

	      (component (type pore)
			 (const  gbar  = 0.003)
			 (output gbar ))
	      
	      (component (type permeating-ion) (name k)
			 (const e = -84.69)
			 (output e ))
	      
	      ) ;; end KV current
	      

	      (component (type voltage-clamp) (name KV)
           
			 (const vchold   = -71)
			 (const vcbase   = -69)
			 (const vcinc    = 10)
			 (const vcsteps  = 8)
			 (const vchdur   = 30)
			 (const vcbdur   = 100)
           
			 (output vchold vcbase vcinc vcsteps vchdur vcbdur)
			 )

))